Merge branch 'for-rmk' of git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux...
[linux-2.6] / drivers / usb / core / hub.c
1 /*
2  * USB hub driver.
3  *
4  * (C) Copyright 1999 Linus Torvalds
5  * (C) Copyright 1999 Johannes Erdfelt
6  * (C) Copyright 1999 Gregory P. Smith
7  * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au)
8  *
9  */
10
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/completion.h>
16 #include <linux/sched.h>
17 #include <linux/list.h>
18 #include <linux/slab.h>
19 #include <linux/ioctl.h>
20 #include <linux/usb.h>
21 #include <linux/usbdevice_fs.h>
22 #include <linux/kthread.h>
23 #include <linux/mutex.h>
24 #include <linux/freezer.h>
25
26 #include <asm/uaccess.h>
27 #include <asm/byteorder.h>
28
29 #include "usb.h"
30 #include "hcd.h"
31 #include "hub.h"
32
33 /* if we are in debug mode, always announce new devices */
34 #ifdef DEBUG
35 #ifndef CONFIG_USB_ANNOUNCE_NEW_DEVICES
36 #define CONFIG_USB_ANNOUNCE_NEW_DEVICES
37 #endif
38 #endif
39
40 struct usb_hub {
41         struct device           *intfdev;       /* the "interface" device */
42         struct usb_device       *hdev;
43         struct kref             kref;
44         struct urb              *urb;           /* for interrupt polling pipe */
45
46         /* buffer for urb ... with extra space in case of babble */
47         char                    (*buffer)[8];
48         dma_addr_t              buffer_dma;     /* DMA address for buffer */
49         union {
50                 struct usb_hub_status   hub;
51                 struct usb_port_status  port;
52         }                       *status;        /* buffer for status reports */
53         struct mutex            status_mutex;   /* for the status buffer */
54
55         int                     error;          /* last reported error */
56         int                     nerrors;        /* track consecutive errors */
57
58         struct list_head        event_list;     /* hubs w/data or errs ready */
59         unsigned long           event_bits[1];  /* status change bitmask */
60         unsigned long           change_bits[1]; /* ports with logical connect
61                                                         status change */
62         unsigned long           busy_bits[1];   /* ports being reset or
63                                                         resumed */
64 #if USB_MAXCHILDREN > 31 /* 8*sizeof(unsigned long) - 1 */
65 #error event_bits[] is too short!
66 #endif
67
68         struct usb_hub_descriptor *descriptor;  /* class descriptor */
69         struct usb_tt           tt;             /* Transaction Translator */
70
71         unsigned                mA_per_port;    /* current for each child */
72
73         unsigned                limited_power:1;
74         unsigned                quiescing:1;
75         unsigned                disconnected:1;
76
77         unsigned                has_indicators:1;
78         u8                      indicator[USB_MAXCHILDREN];
79         struct delayed_work     leds;
80         struct delayed_work     init_work;
81 };
82
83
84 /* Protect struct usb_device->state and ->children members
85  * Note: Both are also protected by ->dev.sem, except that ->state can
86  * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
87 static DEFINE_SPINLOCK(device_state_lock);
88
89 /* khubd's worklist and its lock */
90 static DEFINE_SPINLOCK(hub_event_lock);
91 static LIST_HEAD(hub_event_list);       /* List of hubs needing servicing */
92
93 /* Wakes up khubd */
94 static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);
95
96 static struct task_struct *khubd_task;
97
98 /* cycle leds on hubs that aren't blinking for attention */
99 static int blinkenlights = 0;
100 module_param (blinkenlights, bool, S_IRUGO);
101 MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");
102
103 /*
104  * Device SATA8000 FW1.0 from DATAST0R Technology Corp requires about
105  * 10 seconds to send reply for the initial 64-byte descriptor request.
106  */
107 /* define initial 64-byte descriptor request timeout in milliseconds */
108 static int initial_descriptor_timeout = USB_CTRL_GET_TIMEOUT;
109 module_param(initial_descriptor_timeout, int, S_IRUGO|S_IWUSR);
110 MODULE_PARM_DESC(initial_descriptor_timeout,
111                 "initial 64-byte descriptor request timeout in milliseconds "
112                 "(default 5000 - 5.0 seconds)");
113
114 /*
115  * As of 2.6.10 we introduce a new USB device initialization scheme which
116  * closely resembles the way Windows works.  Hopefully it will be compatible
117  * with a wider range of devices than the old scheme.  However some previously
118  * working devices may start giving rise to "device not accepting address"
119  * errors; if that happens the user can try the old scheme by adjusting the
120  * following module parameters.
121  *
122  * For maximum flexibility there are two boolean parameters to control the
123  * hub driver's behavior.  On the first initialization attempt, if the
124  * "old_scheme_first" parameter is set then the old scheme will be used,
125  * otherwise the new scheme is used.  If that fails and "use_both_schemes"
126  * is set, then the driver will make another attempt, using the other scheme.
127  */
128 static int old_scheme_first = 0;
129 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
130 MODULE_PARM_DESC(old_scheme_first,
131                  "start with the old device initialization scheme");
132
133 static int use_both_schemes = 1;
134 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
135 MODULE_PARM_DESC(use_both_schemes,
136                 "try the other device initialization scheme if the "
137                 "first one fails");
138
139 /* Mutual exclusion for EHCI CF initialization.  This interferes with
140  * port reset on some companion controllers.
141  */
142 DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
143 EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
144
145 #define HUB_DEBOUNCE_TIMEOUT    1500
146 #define HUB_DEBOUNCE_STEP         25
147 #define HUB_DEBOUNCE_STABLE      100
148
149
150 static int usb_reset_and_verify_device(struct usb_device *udev);
151
152 static inline char *portspeed(int portstatus)
153 {
154         if (portstatus & (1 << USB_PORT_FEAT_HIGHSPEED))
155                 return "480 Mb/s";
156         else if (portstatus & (1 << USB_PORT_FEAT_LOWSPEED))
157                 return "1.5 Mb/s";
158         else
159                 return "12 Mb/s";
160 }
161
162 /* Note that hdev or one of its children must be locked! */
163 static inline struct usb_hub *hdev_to_hub(struct usb_device *hdev)
164 {
165         return usb_get_intfdata(hdev->actconfig->interface[0]);
166 }
167
168 /* USB 2.0 spec Section 11.24.4.5 */
169 static int get_hub_descriptor(struct usb_device *hdev, void *data, int size)
170 {
171         int i, ret;
172
173         for (i = 0; i < 3; i++) {
174                 ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
175                         USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
176                         USB_DT_HUB << 8, 0, data, size,
177                         USB_CTRL_GET_TIMEOUT);
178                 if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
179                         return ret;
180         }
181         return -EINVAL;
182 }
183
184 /*
185  * USB 2.0 spec Section 11.24.2.1
186  */
187 static int clear_hub_feature(struct usb_device *hdev, int feature)
188 {
189         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
190                 USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
191 }
192
193 /*
194  * USB 2.0 spec Section 11.24.2.2
195  */
196 static int clear_port_feature(struct usb_device *hdev, int port1, int feature)
197 {
198         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
199                 USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
200                 NULL, 0, 1000);
201 }
202
203 /*
204  * USB 2.0 spec Section 11.24.2.13
205  */
206 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
207 {
208         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
209                 USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
210                 NULL, 0, 1000);
211 }
212
213 /*
214  * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
215  * for info about using port indicators
216  */
217 static void set_port_led(
218         struct usb_hub *hub,
219         int port1,
220         int selector
221 )
222 {
223         int status = set_port_feature(hub->hdev, (selector << 8) | port1,
224                         USB_PORT_FEAT_INDICATOR);
225         if (status < 0)
226                 dev_dbg (hub->intfdev,
227                         "port %d indicator %s status %d\n",
228                         port1,
229                         ({ char *s; switch (selector) {
230                         case HUB_LED_AMBER: s = "amber"; break;
231                         case HUB_LED_GREEN: s = "green"; break;
232                         case HUB_LED_OFF: s = "off"; break;
233                         case HUB_LED_AUTO: s = "auto"; break;
234                         default: s = "??"; break;
235                         }; s; }),
236                         status);
237 }
238
239 #define LED_CYCLE_PERIOD        ((2*HZ)/3)
240
241 static void led_work (struct work_struct *work)
242 {
243         struct usb_hub          *hub =
244                 container_of(work, struct usb_hub, leds.work);
245         struct usb_device       *hdev = hub->hdev;
246         unsigned                i;
247         unsigned                changed = 0;
248         int                     cursor = -1;
249
250         if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
251                 return;
252
253         for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
254                 unsigned        selector, mode;
255
256                 /* 30%-50% duty cycle */
257
258                 switch (hub->indicator[i]) {
259                 /* cycle marker */
260                 case INDICATOR_CYCLE:
261                         cursor = i;
262                         selector = HUB_LED_AUTO;
263                         mode = INDICATOR_AUTO;
264                         break;
265                 /* blinking green = sw attention */
266                 case INDICATOR_GREEN_BLINK:
267                         selector = HUB_LED_GREEN;
268                         mode = INDICATOR_GREEN_BLINK_OFF;
269                         break;
270                 case INDICATOR_GREEN_BLINK_OFF:
271                         selector = HUB_LED_OFF;
272                         mode = INDICATOR_GREEN_BLINK;
273                         break;
274                 /* blinking amber = hw attention */
275                 case INDICATOR_AMBER_BLINK:
276                         selector = HUB_LED_AMBER;
277                         mode = INDICATOR_AMBER_BLINK_OFF;
278                         break;
279                 case INDICATOR_AMBER_BLINK_OFF:
280                         selector = HUB_LED_OFF;
281                         mode = INDICATOR_AMBER_BLINK;
282                         break;
283                 /* blink green/amber = reserved */
284                 case INDICATOR_ALT_BLINK:
285                         selector = HUB_LED_GREEN;
286                         mode = INDICATOR_ALT_BLINK_OFF;
287                         break;
288                 case INDICATOR_ALT_BLINK_OFF:
289                         selector = HUB_LED_AMBER;
290                         mode = INDICATOR_ALT_BLINK;
291                         break;
292                 default:
293                         continue;
294                 }
295                 if (selector != HUB_LED_AUTO)
296                         changed = 1;
297                 set_port_led(hub, i + 1, selector);
298                 hub->indicator[i] = mode;
299         }
300         if (!changed && blinkenlights) {
301                 cursor++;
302                 cursor %= hub->descriptor->bNbrPorts;
303                 set_port_led(hub, cursor + 1, HUB_LED_GREEN);
304                 hub->indicator[cursor] = INDICATOR_CYCLE;
305                 changed++;
306         }
307         if (changed)
308                 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
309 }
310
311 /* use a short timeout for hub/port status fetches */
312 #define USB_STS_TIMEOUT         1000
313 #define USB_STS_RETRIES         5
314
315 /*
316  * USB 2.0 spec Section 11.24.2.6
317  */
318 static int get_hub_status(struct usb_device *hdev,
319                 struct usb_hub_status *data)
320 {
321         int i, status = -ETIMEDOUT;
322
323         for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
324                 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
325                         USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
326                         data, sizeof(*data), USB_STS_TIMEOUT);
327         }
328         return status;
329 }
330
331 /*
332  * USB 2.0 spec Section 11.24.2.7
333  */
334 static int get_port_status(struct usb_device *hdev, int port1,
335                 struct usb_port_status *data)
336 {
337         int i, status = -ETIMEDOUT;
338
339         for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
340                 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
341                         USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
342                         data, sizeof(*data), USB_STS_TIMEOUT);
343         }
344         return status;
345 }
346
347 static int hub_port_status(struct usb_hub *hub, int port1,
348                 u16 *status, u16 *change)
349 {
350         int ret;
351
352         mutex_lock(&hub->status_mutex);
353         ret = get_port_status(hub->hdev, port1, &hub->status->port);
354         if (ret < 4) {
355                 dev_err(hub->intfdev,
356                         "%s failed (err = %d)\n", __func__, ret);
357                 if (ret >= 0)
358                         ret = -EIO;
359         } else {
360                 *status = le16_to_cpu(hub->status->port.wPortStatus);
361                 *change = le16_to_cpu(hub->status->port.wPortChange);
362                 ret = 0;
363         }
364         mutex_unlock(&hub->status_mutex);
365         return ret;
366 }
367
368 static void kick_khubd(struct usb_hub *hub)
369 {
370         unsigned long   flags;
371
372         /* Suppress autosuspend until khubd runs */
373         to_usb_interface(hub->intfdev)->pm_usage_cnt = 1;
374
375         spin_lock_irqsave(&hub_event_lock, flags);
376         if (!hub->disconnected && list_empty(&hub->event_list)) {
377                 list_add_tail(&hub->event_list, &hub_event_list);
378                 wake_up(&khubd_wait);
379         }
380         spin_unlock_irqrestore(&hub_event_lock, flags);
381 }
382
383 void usb_kick_khubd(struct usb_device *hdev)
384 {
385         /* FIXME: What if hdev isn't bound to the hub driver? */
386         kick_khubd(hdev_to_hub(hdev));
387 }
388
389
390 /* completion function, fires on port status changes and various faults */
391 static void hub_irq(struct urb *urb)
392 {
393         struct usb_hub *hub = urb->context;
394         int status = urb->status;
395         unsigned i;
396         unsigned long bits;
397
398         switch (status) {
399         case -ENOENT:           /* synchronous unlink */
400         case -ECONNRESET:       /* async unlink */
401         case -ESHUTDOWN:        /* hardware going away */
402                 return;
403
404         default:                /* presumably an error */
405                 /* Cause a hub reset after 10 consecutive errors */
406                 dev_dbg (hub->intfdev, "transfer --> %d\n", status);
407                 if ((++hub->nerrors < 10) || hub->error)
408                         goto resubmit;
409                 hub->error = status;
410                 /* FALL THROUGH */
411
412         /* let khubd handle things */
413         case 0:                 /* we got data:  port status changed */
414                 bits = 0;
415                 for (i = 0; i < urb->actual_length; ++i)
416                         bits |= ((unsigned long) ((*hub->buffer)[i]))
417                                         << (i*8);
418                 hub->event_bits[0] = bits;
419                 break;
420         }
421
422         hub->nerrors = 0;
423
424         /* Something happened, let khubd figure it out */
425         kick_khubd(hub);
426
427 resubmit:
428         if (hub->quiescing)
429                 return;
430
431         if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
432                         && status != -ENODEV && status != -EPERM)
433                 dev_err (hub->intfdev, "resubmit --> %d\n", status);
434 }
435
436 /* USB 2.0 spec Section 11.24.2.3 */
437 static inline int
438 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
439 {
440         return usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
441                                HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
442                                tt, NULL, 0, 1000);
443 }
444
445 /*
446  * enumeration blocks khubd for a long time. we use keventd instead, since
447  * long blocking there is the exception, not the rule.  accordingly, HCDs
448  * talking to TTs must queue control transfers (not just bulk and iso), so
449  * both can talk to the same hub concurrently.
450  */
451 static void hub_tt_kevent (struct work_struct *work)
452 {
453         struct usb_hub          *hub =
454                 container_of(work, struct usb_hub, tt.kevent);
455         unsigned long           flags;
456         int                     limit = 100;
457
458         spin_lock_irqsave (&hub->tt.lock, flags);
459         while (--limit && !list_empty (&hub->tt.clear_list)) {
460                 struct list_head        *temp;
461                 struct usb_tt_clear     *clear;
462                 struct usb_device       *hdev = hub->hdev;
463                 int                     status;
464
465                 temp = hub->tt.clear_list.next;
466                 clear = list_entry (temp, struct usb_tt_clear, clear_list);
467                 list_del (&clear->clear_list);
468
469                 /* drop lock so HCD can concurrently report other TT errors */
470                 spin_unlock_irqrestore (&hub->tt.lock, flags);
471                 status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
472                 spin_lock_irqsave (&hub->tt.lock, flags);
473
474                 if (status)
475                         dev_err (&hdev->dev,
476                                 "clear tt %d (%04x) error %d\n",
477                                 clear->tt, clear->devinfo, status);
478                 kfree(clear);
479         }
480         spin_unlock_irqrestore (&hub->tt.lock, flags);
481 }
482
483 /**
484  * usb_hub_tt_clear_buffer - clear control/bulk TT state in high speed hub
485  * @udev: the device whose split transaction failed
486  * @pipe: identifies the endpoint of the failed transaction
487  *
488  * High speed HCDs use this to tell the hub driver that some split control or
489  * bulk transaction failed in a way that requires clearing internal state of
490  * a transaction translator.  This is normally detected (and reported) from
491  * interrupt context.
492  *
493  * It may not be possible for that hub to handle additional full (or low)
494  * speed transactions until that state is fully cleared out.
495  */
496 void usb_hub_tt_clear_buffer (struct usb_device *udev, int pipe)
497 {
498         struct usb_tt           *tt = udev->tt;
499         unsigned long           flags;
500         struct usb_tt_clear     *clear;
501
502         /* we've got to cope with an arbitrary number of pending TT clears,
503          * since each TT has "at least two" buffers that can need it (and
504          * there can be many TTs per hub).  even if they're uncommon.
505          */
506         if ((clear = kmalloc (sizeof *clear, GFP_ATOMIC)) == NULL) {
507                 dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
508                 /* FIXME recover somehow ... RESET_TT? */
509                 return;
510         }
511
512         /* info that CLEAR_TT_BUFFER needs */
513         clear->tt = tt->multi ? udev->ttport : 1;
514         clear->devinfo = usb_pipeendpoint (pipe);
515         clear->devinfo |= udev->devnum << 4;
516         clear->devinfo |= usb_pipecontrol (pipe)
517                         ? (USB_ENDPOINT_XFER_CONTROL << 11)
518                         : (USB_ENDPOINT_XFER_BULK << 11);
519         if (usb_pipein (pipe))
520                 clear->devinfo |= 1 << 15;
521         
522         /* tell keventd to clear state for this TT */
523         spin_lock_irqsave (&tt->lock, flags);
524         list_add_tail (&clear->clear_list, &tt->clear_list);
525         schedule_work (&tt->kevent);
526         spin_unlock_irqrestore (&tt->lock, flags);
527 }
528 EXPORT_SYMBOL_GPL(usb_hub_tt_clear_buffer);
529
530 /* If do_delay is false, return the number of milliseconds the caller
531  * needs to delay.
532  */
533 static unsigned hub_power_on(struct usb_hub *hub, bool do_delay)
534 {
535         int port1;
536         unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
537         unsigned delay;
538         u16 wHubCharacteristics =
539                         le16_to_cpu(hub->descriptor->wHubCharacteristics);
540
541         /* Enable power on each port.  Some hubs have reserved values
542          * of LPSM (> 2) in their descriptors, even though they are
543          * USB 2.0 hubs.  Some hubs do not implement port-power switching
544          * but only emulate it.  In all cases, the ports won't work
545          * unless we send these messages to the hub.
546          */
547         if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2)
548                 dev_dbg(hub->intfdev, "enabling power on all ports\n");
549         else
550                 dev_dbg(hub->intfdev, "trying to enable port power on "
551                                 "non-switchable hub\n");
552         for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
553                 set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
554
555         /* Wait at least 100 msec for power to become stable */
556         delay = max(pgood_delay, (unsigned) 100);
557         if (do_delay)
558                 msleep(delay);
559         return delay;
560 }
561
562 static int hub_hub_status(struct usb_hub *hub,
563                 u16 *status, u16 *change)
564 {
565         int ret;
566
567         mutex_lock(&hub->status_mutex);
568         ret = get_hub_status(hub->hdev, &hub->status->hub);
569         if (ret < 0)
570                 dev_err (hub->intfdev,
571                         "%s failed (err = %d)\n", __func__, ret);
572         else {
573                 *status = le16_to_cpu(hub->status->hub.wHubStatus);
574                 *change = le16_to_cpu(hub->status->hub.wHubChange); 
575                 ret = 0;
576         }
577         mutex_unlock(&hub->status_mutex);
578         return ret;
579 }
580
581 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
582 {
583         struct usb_device *hdev = hub->hdev;
584         int ret = 0;
585
586         if (hdev->children[port1-1] && set_state)
587                 usb_set_device_state(hdev->children[port1-1],
588                                 USB_STATE_NOTATTACHED);
589         if (!hub->error)
590                 ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
591         if (ret)
592                 dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
593                                 port1, ret);
594         return ret;
595 }
596
597 /*
598  * Disable a port and mark a logical connnect-change event, so that some
599  * time later khubd will disconnect() any existing usb_device on the port
600  * and will re-enumerate if there actually is a device attached.
601  */
602 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
603 {
604         dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
605         hub_port_disable(hub, port1, 1);
606
607         /* FIXME let caller ask to power down the port:
608          *  - some devices won't enumerate without a VBUS power cycle
609          *  - SRP saves power that way
610          *  - ... new call, TBD ...
611          * That's easy if this hub can switch power per-port, and
612          * khubd reactivates the port later (timer, SRP, etc).
613          * Powerdown must be optional, because of reset/DFU.
614          */
615
616         set_bit(port1, hub->change_bits);
617         kick_khubd(hub);
618 }
619
620 enum hub_activation_type {
621         HUB_INIT, HUB_INIT2, HUB_INIT3,
622         HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,
623 };
624
625 static void hub_init_func2(struct work_struct *ws);
626 static void hub_init_func3(struct work_struct *ws);
627
628 static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
629 {
630         struct usb_device *hdev = hub->hdev;
631         int port1;
632         int status;
633         bool need_debounce_delay = false;
634         unsigned delay;
635
636         /* Continue a partial initialization */
637         if (type == HUB_INIT2)
638                 goto init2;
639         if (type == HUB_INIT3)
640                 goto init3;
641
642         /* After a resume, port power should still be on.
643          * For any other type of activation, turn it on.
644          */
645         if (type != HUB_RESUME) {
646
647                 /* Speed up system boot by using a delayed_work for the
648                  * hub's initial power-up delays.  This is pretty awkward
649                  * and the implementation looks like a home-brewed sort of
650                  * setjmp/longjmp, but it saves at least 100 ms for each
651                  * root hub (assuming usbcore is compiled into the kernel
652                  * rather than as a module).  It adds up.
653                  *
654                  * This can't be done for HUB_RESUME or HUB_RESET_RESUME
655                  * because for those activation types the ports have to be
656                  * operational when we return.  In theory this could be done
657                  * for HUB_POST_RESET, but it's easier not to.
658                  */
659                 if (type == HUB_INIT) {
660                         delay = hub_power_on(hub, false);
661                         PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func2);
662                         schedule_delayed_work(&hub->init_work,
663                                         msecs_to_jiffies(delay));
664
665                         /* Suppress autosuspend until init is done */
666                         to_usb_interface(hub->intfdev)->pm_usage_cnt = 1;
667                         return;         /* Continues at init2: below */
668                 } else {
669                         hub_power_on(hub, true);
670                 }
671         }
672  init2:
673
674         /* Check each port and set hub->change_bits to let khubd know
675          * which ports need attention.
676          */
677         for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
678                 struct usb_device *udev = hdev->children[port1-1];
679                 u16 portstatus, portchange;
680
681                 portstatus = portchange = 0;
682                 status = hub_port_status(hub, port1, &portstatus, &portchange);
683                 if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
684                         dev_dbg(hub->intfdev,
685                                         "port %d: status %04x change %04x\n",
686                                         port1, portstatus, portchange);
687
688                 /* After anything other than HUB_RESUME (i.e., initialization
689                  * or any sort of reset), every port should be disabled.
690                  * Unconnected ports should likewise be disabled (paranoia),
691                  * and so should ports for which we have no usb_device.
692                  */
693                 if ((portstatus & USB_PORT_STAT_ENABLE) && (
694                                 type != HUB_RESUME ||
695                                 !(portstatus & USB_PORT_STAT_CONNECTION) ||
696                                 !udev ||
697                                 udev->state == USB_STATE_NOTATTACHED)) {
698                         clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
699                         portstatus &= ~USB_PORT_STAT_ENABLE;
700                 }
701
702                 /* Clear status-change flags; we'll debounce later */
703                 if (portchange & USB_PORT_STAT_C_CONNECTION) {
704                         need_debounce_delay = true;
705                         clear_port_feature(hub->hdev, port1,
706                                         USB_PORT_FEAT_C_CONNECTION);
707                 }
708                 if (portchange & USB_PORT_STAT_C_ENABLE) {
709                         need_debounce_delay = true;
710                         clear_port_feature(hub->hdev, port1,
711                                         USB_PORT_FEAT_C_ENABLE);
712                 }
713
714                 if (!udev || udev->state == USB_STATE_NOTATTACHED) {
715                         /* Tell khubd to disconnect the device or
716                          * check for a new connection
717                          */
718                         if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
719                                 set_bit(port1, hub->change_bits);
720
721                 } else if (portstatus & USB_PORT_STAT_ENABLE) {
722                         /* The power session apparently survived the resume.
723                          * If there was an overcurrent or suspend change
724                          * (i.e., remote wakeup request), have khubd
725                          * take care of it.
726                          */
727                         if (portchange)
728                                 set_bit(port1, hub->change_bits);
729
730                 } else if (udev->persist_enabled) {
731 #ifdef CONFIG_PM
732                         udev->reset_resume = 1;
733 #endif
734                         set_bit(port1, hub->change_bits);
735
736                 } else {
737                         /* The power session is gone; tell khubd */
738                         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
739                         set_bit(port1, hub->change_bits);
740                 }
741         }
742
743         /* If no port-status-change flags were set, we don't need any
744          * debouncing.  If flags were set we can try to debounce the
745          * ports all at once right now, instead of letting khubd do them
746          * one at a time later on.
747          *
748          * If any port-status changes do occur during this delay, khubd
749          * will see them later and handle them normally.
750          */
751         if (need_debounce_delay) {
752                 delay = HUB_DEBOUNCE_STABLE;
753
754                 /* Don't do a long sleep inside a workqueue routine */
755                 if (type == HUB_INIT2) {
756                         PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func3);
757                         schedule_delayed_work(&hub->init_work,
758                                         msecs_to_jiffies(delay));
759                         return;         /* Continues at init3: below */
760                 } else {
761                         msleep(delay);
762                 }
763         }
764  init3:
765         hub->quiescing = 0;
766
767         status = usb_submit_urb(hub->urb, GFP_NOIO);
768         if (status < 0)
769                 dev_err(hub->intfdev, "activate --> %d\n", status);
770         if (hub->has_indicators && blinkenlights)
771                 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
772
773         /* Scan all ports that need attention */
774         kick_khubd(hub);
775 }
776
777 /* Implement the continuations for the delays above */
778 static void hub_init_func2(struct work_struct *ws)
779 {
780         struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
781
782         hub_activate(hub, HUB_INIT2);
783 }
784
785 static void hub_init_func3(struct work_struct *ws)
786 {
787         struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
788
789         hub_activate(hub, HUB_INIT3);
790 }
791
792 enum hub_quiescing_type {
793         HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
794 };
795
796 static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
797 {
798         struct usb_device *hdev = hub->hdev;
799         int i;
800
801         cancel_delayed_work_sync(&hub->init_work);
802
803         /* khubd and related activity won't re-trigger */
804         hub->quiescing = 1;
805
806         if (type != HUB_SUSPEND) {
807                 /* Disconnect all the children */
808                 for (i = 0; i < hdev->maxchild; ++i) {
809                         if (hdev->children[i])
810                                 usb_disconnect(&hdev->children[i]);
811                 }
812         }
813
814         /* Stop khubd and related activity */
815         usb_kill_urb(hub->urb);
816         if (hub->has_indicators)
817                 cancel_delayed_work_sync(&hub->leds);
818         if (hub->tt.hub)
819                 cancel_work_sync(&hub->tt.kevent);
820 }
821
822 /* caller has locked the hub device */
823 static int hub_pre_reset(struct usb_interface *intf)
824 {
825         struct usb_hub *hub = usb_get_intfdata(intf);
826
827         hub_quiesce(hub, HUB_PRE_RESET);
828         return 0;
829 }
830
831 /* caller has locked the hub device */
832 static int hub_post_reset(struct usb_interface *intf)
833 {
834         struct usb_hub *hub = usb_get_intfdata(intf);
835
836         hub_activate(hub, HUB_POST_RESET);
837         return 0;
838 }
839
840 static int hub_configure(struct usb_hub *hub,
841         struct usb_endpoint_descriptor *endpoint)
842 {
843         struct usb_device *hdev = hub->hdev;
844         struct device *hub_dev = hub->intfdev;
845         u16 hubstatus, hubchange;
846         u16 wHubCharacteristics;
847         unsigned int pipe;
848         int maxp, ret;
849         char *message;
850
851         hub->buffer = usb_buffer_alloc(hdev, sizeof(*hub->buffer), GFP_KERNEL,
852                         &hub->buffer_dma);
853         if (!hub->buffer) {
854                 message = "can't allocate hub irq buffer";
855                 ret = -ENOMEM;
856                 goto fail;
857         }
858
859         hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
860         if (!hub->status) {
861                 message = "can't kmalloc hub status buffer";
862                 ret = -ENOMEM;
863                 goto fail;
864         }
865         mutex_init(&hub->status_mutex);
866
867         hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
868         if (!hub->descriptor) {
869                 message = "can't kmalloc hub descriptor";
870                 ret = -ENOMEM;
871                 goto fail;
872         }
873
874         /* Request the entire hub descriptor.
875          * hub->descriptor can handle USB_MAXCHILDREN ports,
876          * but the hub can/will return fewer bytes here.
877          */
878         ret = get_hub_descriptor(hdev, hub->descriptor,
879                         sizeof(*hub->descriptor));
880         if (ret < 0) {
881                 message = "can't read hub descriptor";
882                 goto fail;
883         } else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
884                 message = "hub has too many ports!";
885                 ret = -ENODEV;
886                 goto fail;
887         }
888
889         hdev->maxchild = hub->descriptor->bNbrPorts;
890         dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
891                 (hdev->maxchild == 1) ? "" : "s");
892
893         wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
894
895         if (wHubCharacteristics & HUB_CHAR_COMPOUND) {
896                 int     i;
897                 char    portstr [USB_MAXCHILDREN + 1];
898
899                 for (i = 0; i < hdev->maxchild; i++)
900                         portstr[i] = hub->descriptor->DeviceRemovable
901                                     [((i + 1) / 8)] & (1 << ((i + 1) % 8))
902                                 ? 'F' : 'R';
903                 portstr[hdev->maxchild] = 0;
904                 dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
905         } else
906                 dev_dbg(hub_dev, "standalone hub\n");
907
908         switch (wHubCharacteristics & HUB_CHAR_LPSM) {
909                 case 0x00:
910                         dev_dbg(hub_dev, "ganged power switching\n");
911                         break;
912                 case 0x01:
913                         dev_dbg(hub_dev, "individual port power switching\n");
914                         break;
915                 case 0x02:
916                 case 0x03:
917                         dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
918                         break;
919         }
920
921         switch (wHubCharacteristics & HUB_CHAR_OCPM) {
922                 case 0x00:
923                         dev_dbg(hub_dev, "global over-current protection\n");
924                         break;
925                 case 0x08:
926                         dev_dbg(hub_dev, "individual port over-current protection\n");
927                         break;
928                 case 0x10:
929                 case 0x18:
930                         dev_dbg(hub_dev, "no over-current protection\n");
931                         break;
932         }
933
934         spin_lock_init (&hub->tt.lock);
935         INIT_LIST_HEAD (&hub->tt.clear_list);
936         INIT_WORK (&hub->tt.kevent, hub_tt_kevent);
937         switch (hdev->descriptor.bDeviceProtocol) {
938                 case 0:
939                         break;
940                 case 1:
941                         dev_dbg(hub_dev, "Single TT\n");
942                         hub->tt.hub = hdev;
943                         break;
944                 case 2:
945                         ret = usb_set_interface(hdev, 0, 1);
946                         if (ret == 0) {
947                                 dev_dbg(hub_dev, "TT per port\n");
948                                 hub->tt.multi = 1;
949                         } else
950                                 dev_err(hub_dev, "Using single TT (err %d)\n",
951                                         ret);
952                         hub->tt.hub = hdev;
953                         break;
954                 default:
955                         dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
956                                 hdev->descriptor.bDeviceProtocol);
957                         break;
958         }
959
960         /* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
961         switch (wHubCharacteristics & HUB_CHAR_TTTT) {
962                 case HUB_TTTT_8_BITS:
963                         if (hdev->descriptor.bDeviceProtocol != 0) {
964                                 hub->tt.think_time = 666;
965                                 dev_dbg(hub_dev, "TT requires at most %d "
966                                                 "FS bit times (%d ns)\n",
967                                         8, hub->tt.think_time);
968                         }
969                         break;
970                 case HUB_TTTT_16_BITS:
971                         hub->tt.think_time = 666 * 2;
972                         dev_dbg(hub_dev, "TT requires at most %d "
973                                         "FS bit times (%d ns)\n",
974                                 16, hub->tt.think_time);
975                         break;
976                 case HUB_TTTT_24_BITS:
977                         hub->tt.think_time = 666 * 3;
978                         dev_dbg(hub_dev, "TT requires at most %d "
979                                         "FS bit times (%d ns)\n",
980                                 24, hub->tt.think_time);
981                         break;
982                 case HUB_TTTT_32_BITS:
983                         hub->tt.think_time = 666 * 4;
984                         dev_dbg(hub_dev, "TT requires at most %d "
985                                         "FS bit times (%d ns)\n",
986                                 32, hub->tt.think_time);
987                         break;
988         }
989
990         /* probe() zeroes hub->indicator[] */
991         if (wHubCharacteristics & HUB_CHAR_PORTIND) {
992                 hub->has_indicators = 1;
993                 dev_dbg(hub_dev, "Port indicators are supported\n");
994         }
995
996         dev_dbg(hub_dev, "power on to power good time: %dms\n",
997                 hub->descriptor->bPwrOn2PwrGood * 2);
998
999         /* power budgeting mostly matters with bus-powered hubs,
1000          * and battery-powered root hubs (may provide just 8 mA).
1001          */
1002         ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
1003         if (ret < 2) {
1004                 message = "can't get hub status";
1005                 goto fail;
1006         }
1007         le16_to_cpus(&hubstatus);
1008         if (hdev == hdev->bus->root_hub) {
1009                 if (hdev->bus_mA == 0 || hdev->bus_mA >= 500)
1010                         hub->mA_per_port = 500;
1011                 else {
1012                         hub->mA_per_port = hdev->bus_mA;
1013                         hub->limited_power = 1;
1014                 }
1015         } else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
1016                 dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
1017                         hub->descriptor->bHubContrCurrent);
1018                 hub->limited_power = 1;
1019                 if (hdev->maxchild > 0) {
1020                         int remaining = hdev->bus_mA -
1021                                         hub->descriptor->bHubContrCurrent;
1022
1023                         if (remaining < hdev->maxchild * 100)
1024                                 dev_warn(hub_dev,
1025                                         "insufficient power available "
1026                                         "to use all downstream ports\n");
1027                         hub->mA_per_port = 100;         /* 7.2.1.1 */
1028                 }
1029         } else {        /* Self-powered external hub */
1030                 /* FIXME: What about battery-powered external hubs that
1031                  * provide less current per port? */
1032                 hub->mA_per_port = 500;
1033         }
1034         if (hub->mA_per_port < 500)
1035                 dev_dbg(hub_dev, "%umA bus power budget for each child\n",
1036                                 hub->mA_per_port);
1037
1038         ret = hub_hub_status(hub, &hubstatus, &hubchange);
1039         if (ret < 0) {
1040                 message = "can't get hub status";
1041                 goto fail;
1042         }
1043
1044         /* local power status reports aren't always correct */
1045         if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
1046                 dev_dbg(hub_dev, "local power source is %s\n",
1047                         (hubstatus & HUB_STATUS_LOCAL_POWER)
1048                         ? "lost (inactive)" : "good");
1049
1050         if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
1051                 dev_dbg(hub_dev, "%sover-current condition exists\n",
1052                         (hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
1053
1054         /* set up the interrupt endpoint
1055          * We use the EP's maxpacket size instead of (PORTS+1+7)/8
1056          * bytes as USB2.0[11.12.3] says because some hubs are known
1057          * to send more data (and thus cause overflow). For root hubs,
1058          * maxpktsize is defined in hcd.c's fake endpoint descriptors
1059          * to be big enough for at least USB_MAXCHILDREN ports. */
1060         pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
1061         maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
1062
1063         if (maxp > sizeof(*hub->buffer))
1064                 maxp = sizeof(*hub->buffer);
1065
1066         hub->urb = usb_alloc_urb(0, GFP_KERNEL);
1067         if (!hub->urb) {
1068                 message = "couldn't allocate interrupt urb";
1069                 ret = -ENOMEM;
1070                 goto fail;
1071         }
1072
1073         usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
1074                 hub, endpoint->bInterval);
1075         hub->urb->transfer_dma = hub->buffer_dma;
1076         hub->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1077
1078         /* maybe cycle the hub leds */
1079         if (hub->has_indicators && blinkenlights)
1080                 hub->indicator [0] = INDICATOR_CYCLE;
1081
1082         hub_activate(hub, HUB_INIT);
1083         return 0;
1084
1085 fail:
1086         dev_err (hub_dev, "config failed, %s (err %d)\n",
1087                         message, ret);
1088         /* hub_disconnect() frees urb and descriptor */
1089         return ret;
1090 }
1091
1092 static void hub_release(struct kref *kref)
1093 {
1094         struct usb_hub *hub = container_of(kref, struct usb_hub, kref);
1095
1096         usb_put_intf(to_usb_interface(hub->intfdev));
1097         kfree(hub);
1098 }
1099
1100 static unsigned highspeed_hubs;
1101
1102 static void hub_disconnect(struct usb_interface *intf)
1103 {
1104         struct usb_hub *hub = usb_get_intfdata (intf);
1105
1106         /* Take the hub off the event list and don't let it be added again */
1107         spin_lock_irq(&hub_event_lock);
1108         list_del_init(&hub->event_list);
1109         hub->disconnected = 1;
1110         spin_unlock_irq(&hub_event_lock);
1111
1112         /* Disconnect all children and quiesce the hub */
1113         hub->error = 0;
1114         hub_quiesce(hub, HUB_DISCONNECT);
1115
1116         usb_set_intfdata (intf, NULL);
1117
1118         if (hub->hdev->speed == USB_SPEED_HIGH)
1119                 highspeed_hubs--;
1120
1121         usb_free_urb(hub->urb);
1122         kfree(hub->descriptor);
1123         kfree(hub->status);
1124         usb_buffer_free(hub->hdev, sizeof(*hub->buffer), hub->buffer,
1125                         hub->buffer_dma);
1126
1127         kref_put(&hub->kref, hub_release);
1128 }
1129
1130 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
1131 {
1132         struct usb_host_interface *desc;
1133         struct usb_endpoint_descriptor *endpoint;
1134         struct usb_device *hdev;
1135         struct usb_hub *hub;
1136
1137         desc = intf->cur_altsetting;
1138         hdev = interface_to_usbdev(intf);
1139
1140         if (hdev->level == MAX_TOPO_LEVEL) {
1141                 dev_err(&intf->dev,
1142                         "Unsupported bus topology: hub nested too deep\n");
1143                 return -E2BIG;
1144         }
1145
1146 #ifdef  CONFIG_USB_OTG_BLACKLIST_HUB
1147         if (hdev->parent) {
1148                 dev_warn(&intf->dev, "ignoring external hub\n");
1149                 return -ENODEV;
1150         }
1151 #endif
1152
1153         /* Some hubs have a subclass of 1, which AFAICT according to the */
1154         /*  specs is not defined, but it works */
1155         if ((desc->desc.bInterfaceSubClass != 0) &&
1156             (desc->desc.bInterfaceSubClass != 1)) {
1157 descriptor_error:
1158                 dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
1159                 return -EIO;
1160         }
1161
1162         /* Multiple endpoints? What kind of mutant ninja-hub is this? */
1163         if (desc->desc.bNumEndpoints != 1)
1164                 goto descriptor_error;
1165
1166         endpoint = &desc->endpoint[0].desc;
1167
1168         /* If it's not an interrupt in endpoint, we'd better punt! */
1169         if (!usb_endpoint_is_int_in(endpoint))
1170                 goto descriptor_error;
1171
1172         /* We found a hub */
1173         dev_info (&intf->dev, "USB hub found\n");
1174
1175         hub = kzalloc(sizeof(*hub), GFP_KERNEL);
1176         if (!hub) {
1177                 dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
1178                 return -ENOMEM;
1179         }
1180
1181         kref_init(&hub->kref);
1182         INIT_LIST_HEAD(&hub->event_list);
1183         hub->intfdev = &intf->dev;
1184         hub->hdev = hdev;
1185         INIT_DELAYED_WORK(&hub->leds, led_work);
1186         INIT_DELAYED_WORK(&hub->init_work, NULL);
1187         usb_get_intf(intf);
1188
1189         usb_set_intfdata (intf, hub);
1190         intf->needs_remote_wakeup = 1;
1191
1192         if (hdev->speed == USB_SPEED_HIGH)
1193                 highspeed_hubs++;
1194
1195         if (hub_configure(hub, endpoint) >= 0)
1196                 return 0;
1197
1198         hub_disconnect (intf);
1199         return -ENODEV;
1200 }
1201
1202 static int
1203 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
1204 {
1205         struct usb_device *hdev = interface_to_usbdev (intf);
1206
1207         /* assert ifno == 0 (part of hub spec) */
1208         switch (code) {
1209         case USBDEVFS_HUB_PORTINFO: {
1210                 struct usbdevfs_hub_portinfo *info = user_data;
1211                 int i;
1212
1213                 spin_lock_irq(&device_state_lock);
1214                 if (hdev->devnum <= 0)
1215                         info->nports = 0;
1216                 else {
1217                         info->nports = hdev->maxchild;
1218                         for (i = 0; i < info->nports; i++) {
1219                                 if (hdev->children[i] == NULL)
1220                                         info->port[i] = 0;
1221                                 else
1222                                         info->port[i] =
1223                                                 hdev->children[i]->devnum;
1224                         }
1225                 }
1226                 spin_unlock_irq(&device_state_lock);
1227
1228                 return info->nports + 1;
1229                 }
1230
1231         default:
1232                 return -ENOSYS;
1233         }
1234 }
1235
1236
1237 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
1238 {
1239         int i;
1240
1241         for (i = 0; i < udev->maxchild; ++i) {
1242                 if (udev->children[i])
1243                         recursively_mark_NOTATTACHED(udev->children[i]);
1244         }
1245         if (udev->state == USB_STATE_SUSPENDED) {
1246                 udev->discon_suspended = 1;
1247                 udev->active_duration -= jiffies;
1248         }
1249         udev->state = USB_STATE_NOTATTACHED;
1250 }
1251
1252 /**
1253  * usb_set_device_state - change a device's current state (usbcore, hcds)
1254  * @udev: pointer to device whose state should be changed
1255  * @new_state: new state value to be stored
1256  *
1257  * udev->state is _not_ fully protected by the device lock.  Although
1258  * most transitions are made only while holding the lock, the state can
1259  * can change to USB_STATE_NOTATTACHED at almost any time.  This
1260  * is so that devices can be marked as disconnected as soon as possible,
1261  * without having to wait for any semaphores to be released.  As a result,
1262  * all changes to any device's state must be protected by the
1263  * device_state_lock spinlock.
1264  *
1265  * Once a device has been added to the device tree, all changes to its state
1266  * should be made using this routine.  The state should _not_ be set directly.
1267  *
1268  * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
1269  * Otherwise udev->state is set to new_state, and if new_state is
1270  * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
1271  * to USB_STATE_NOTATTACHED.
1272  */
1273 void usb_set_device_state(struct usb_device *udev,
1274                 enum usb_device_state new_state)
1275 {
1276         unsigned long flags;
1277
1278         spin_lock_irqsave(&device_state_lock, flags);
1279         if (udev->state == USB_STATE_NOTATTACHED)
1280                 ;       /* do nothing */
1281         else if (new_state != USB_STATE_NOTATTACHED) {
1282
1283                 /* root hub wakeup capabilities are managed out-of-band
1284                  * and may involve silicon errata ... ignore them here.
1285                  */
1286                 if (udev->parent) {
1287                         if (udev->state == USB_STATE_SUSPENDED
1288                                         || new_state == USB_STATE_SUSPENDED)
1289                                 ;       /* No change to wakeup settings */
1290                         else if (new_state == USB_STATE_CONFIGURED)
1291                                 device_init_wakeup(&udev->dev,
1292                                         (udev->actconfig->desc.bmAttributes
1293                                          & USB_CONFIG_ATT_WAKEUP));
1294                         else
1295                                 device_init_wakeup(&udev->dev, 0);
1296                 }
1297                 if (udev->state == USB_STATE_SUSPENDED &&
1298                         new_state != USB_STATE_SUSPENDED)
1299                         udev->active_duration -= jiffies;
1300                 else if (new_state == USB_STATE_SUSPENDED &&
1301                                 udev->state != USB_STATE_SUSPENDED)
1302                         udev->active_duration += jiffies;
1303                 udev->state = new_state;
1304         } else
1305                 recursively_mark_NOTATTACHED(udev);
1306         spin_unlock_irqrestore(&device_state_lock, flags);
1307 }
1308 EXPORT_SYMBOL_GPL(usb_set_device_state);
1309
1310 /*
1311  * WUSB devices are simple: they have no hubs behind, so the mapping
1312  * device <-> virtual port number becomes 1:1. Why? to simplify the
1313  * life of the device connection logic in
1314  * drivers/usb/wusbcore/devconnect.c. When we do the initial secret
1315  * handshake we need to assign a temporary address in the unauthorized
1316  * space. For simplicity we use the first virtual port number found to
1317  * be free [drivers/usb/wusbcore/devconnect.c:wusbhc_devconnect_ack()]
1318  * and that becomes it's address [X < 128] or its unauthorized address
1319  * [X | 0x80].
1320  *
1321  * We add 1 as an offset to the one-based USB-stack port number
1322  * (zero-based wusb virtual port index) for two reasons: (a) dev addr
1323  * 0 is reserved by USB for default address; (b) Linux's USB stack
1324  * uses always #1 for the root hub of the controller. So USB stack's
1325  * port #1, which is wusb virtual-port #0 has address #2.
1326  */
1327 static void choose_address(struct usb_device *udev)
1328 {
1329         int             devnum;
1330         struct usb_bus  *bus = udev->bus;
1331
1332         /* If khubd ever becomes multithreaded, this will need a lock */
1333         if (udev->wusb) {
1334                 devnum = udev->portnum + 1;
1335                 BUG_ON(test_bit(devnum, bus->devmap.devicemap));
1336         } else {
1337                 /* Try to allocate the next devnum beginning at
1338                  * bus->devnum_next. */
1339                 devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
1340                                             bus->devnum_next);
1341                 if (devnum >= 128)
1342                         devnum = find_next_zero_bit(bus->devmap.devicemap,
1343                                                     128, 1);
1344                 bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
1345         }
1346         if (devnum < 128) {
1347                 set_bit(devnum, bus->devmap.devicemap);
1348                 udev->devnum = devnum;
1349         }
1350 }
1351
1352 static void release_address(struct usb_device *udev)
1353 {
1354         if (udev->devnum > 0) {
1355                 clear_bit(udev->devnum, udev->bus->devmap.devicemap);
1356                 udev->devnum = -1;
1357         }
1358 }
1359
1360 static void update_address(struct usb_device *udev, int devnum)
1361 {
1362         /* The address for a WUSB device is managed by wusbcore. */
1363         if (!udev->wusb)
1364                 udev->devnum = devnum;
1365 }
1366
1367 #ifdef  CONFIG_USB_SUSPEND
1368
1369 static void usb_stop_pm(struct usb_device *udev)
1370 {
1371         /* Synchronize with the ksuspend thread to prevent any more
1372          * autosuspend requests from being submitted, and decrement
1373          * the parent's count of unsuspended children.
1374          */
1375         usb_pm_lock(udev);
1376         if (udev->parent && !udev->discon_suspended)
1377                 usb_autosuspend_device(udev->parent);
1378         usb_pm_unlock(udev);
1379
1380         /* Stop any autosuspend or autoresume requests already submitted */
1381         cancel_delayed_work_sync(&udev->autosuspend);
1382         cancel_work_sync(&udev->autoresume);
1383 }
1384
1385 #else
1386
1387 static inline void usb_stop_pm(struct usb_device *udev)
1388 { }
1389
1390 #endif
1391
1392 /**
1393  * usb_disconnect - disconnect a device (usbcore-internal)
1394  * @pdev: pointer to device being disconnected
1395  * Context: !in_interrupt ()
1396  *
1397  * Something got disconnected. Get rid of it and all of its children.
1398  *
1399  * If *pdev is a normal device then the parent hub must already be locked.
1400  * If *pdev is a root hub then this routine will acquire the
1401  * usb_bus_list_lock on behalf of the caller.
1402  *
1403  * Only hub drivers (including virtual root hub drivers for host
1404  * controllers) should ever call this.
1405  *
1406  * This call is synchronous, and may not be used in an interrupt context.
1407  */
1408 void usb_disconnect(struct usb_device **pdev)
1409 {
1410         struct usb_device       *udev = *pdev;
1411         int                     i;
1412
1413         if (!udev) {
1414                 pr_debug ("%s nodev\n", __func__);
1415                 return;
1416         }
1417
1418         /* mark the device as inactive, so any further urb submissions for
1419          * this device (and any of its children) will fail immediately.
1420          * this quiesces everyting except pending urbs.
1421          */
1422         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1423         dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum);
1424
1425         usb_lock_device(udev);
1426
1427         /* Free up all the children before we remove this device */
1428         for (i = 0; i < USB_MAXCHILDREN; i++) {
1429                 if (udev->children[i])
1430                         usb_disconnect(&udev->children[i]);
1431         }
1432
1433         /* deallocate hcd/hardware state ... nuking all pending urbs and
1434          * cleaning up all state associated with the current configuration
1435          * so that the hardware is now fully quiesced.
1436          */
1437         dev_dbg (&udev->dev, "unregistering device\n");
1438         usb_disable_device(udev, 0);
1439         usb_hcd_synchronize_unlinks(udev);
1440
1441         usb_remove_ep_devs(&udev->ep0);
1442         usb_unlock_device(udev);
1443
1444         /* Unregister the device.  The device driver is responsible
1445          * for de-configuring the device and invoking the remove-device
1446          * notifier chain (used by usbfs and possibly others).
1447          */
1448         device_del(&udev->dev);
1449
1450         /* Free the device number and delete the parent's children[]
1451          * (or root_hub) pointer.
1452          */
1453         release_address(udev);
1454
1455         /* Avoid races with recursively_mark_NOTATTACHED() */
1456         spin_lock_irq(&device_state_lock);
1457         *pdev = NULL;
1458         spin_unlock_irq(&device_state_lock);
1459
1460         usb_stop_pm(udev);
1461
1462         put_device(&udev->dev);
1463 }
1464
1465 #ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
1466 static void show_string(struct usb_device *udev, char *id, char *string)
1467 {
1468         if (!string)
1469                 return;
1470         dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string);
1471 }
1472
1473 static void announce_device(struct usb_device *udev)
1474 {
1475         dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n",
1476                 le16_to_cpu(udev->descriptor.idVendor),
1477                 le16_to_cpu(udev->descriptor.idProduct));
1478         dev_info(&udev->dev,
1479                 "New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
1480                 udev->descriptor.iManufacturer,
1481                 udev->descriptor.iProduct,
1482                 udev->descriptor.iSerialNumber);
1483         show_string(udev, "Product", udev->product);
1484         show_string(udev, "Manufacturer", udev->manufacturer);
1485         show_string(udev, "SerialNumber", udev->serial);
1486 }
1487 #else
1488 static inline void announce_device(struct usb_device *udev) { }
1489 #endif
1490
1491 #ifdef  CONFIG_USB_OTG
1492 #include "otg_whitelist.h"
1493 #endif
1494
1495 /**
1496  * usb_configure_device_otg - FIXME (usbcore-internal)
1497  * @udev: newly addressed device (in ADDRESS state)
1498  *
1499  * Do configuration for On-The-Go devices
1500  */
1501 static int usb_configure_device_otg(struct usb_device *udev)
1502 {
1503         int err = 0;
1504
1505 #ifdef  CONFIG_USB_OTG
1506         /*
1507          * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
1508          * to wake us after we've powered off VBUS; and HNP, switching roles
1509          * "host" to "peripheral".  The OTG descriptor helps figure this out.
1510          */
1511         if (!udev->bus->is_b_host
1512                         && udev->config
1513                         && udev->parent == udev->bus->root_hub) {
1514                 struct usb_otg_descriptor       *desc = 0;
1515                 struct usb_bus                  *bus = udev->bus;
1516
1517                 /* descriptor may appear anywhere in config */
1518                 if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
1519                                         le16_to_cpu(udev->config[0].desc.wTotalLength),
1520                                         USB_DT_OTG, (void **) &desc) == 0) {
1521                         if (desc->bmAttributes & USB_OTG_HNP) {
1522                                 unsigned                port1 = udev->portnum;
1523
1524                                 dev_info(&udev->dev,
1525                                         "Dual-Role OTG device on %sHNP port\n",
1526                                         (port1 == bus->otg_port)
1527                                                 ? "" : "non-");
1528
1529                                 /* enable HNP before suspend, it's simpler */
1530                                 if (port1 == bus->otg_port)
1531                                         bus->b_hnp_enable = 1;
1532                                 err = usb_control_msg(udev,
1533                                         usb_sndctrlpipe(udev, 0),
1534                                         USB_REQ_SET_FEATURE, 0,
1535                                         bus->b_hnp_enable
1536                                                 ? USB_DEVICE_B_HNP_ENABLE
1537                                                 : USB_DEVICE_A_ALT_HNP_SUPPORT,
1538                                         0, NULL, 0, USB_CTRL_SET_TIMEOUT);
1539                                 if (err < 0) {
1540                                         /* OTG MESSAGE: report errors here,
1541                                          * customize to match your product.
1542                                          */
1543                                         dev_info(&udev->dev,
1544                                                 "can't set HNP mode: %d\n",
1545                                                 err);
1546                                         bus->b_hnp_enable = 0;
1547                                 }
1548                         }
1549                 }
1550         }
1551
1552         if (!is_targeted(udev)) {
1553
1554                 /* Maybe it can talk to us, though we can't talk to it.
1555                  * (Includes HNP test device.)
1556                  */
1557                 if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
1558                         err = usb_port_suspend(udev, PMSG_SUSPEND);
1559                         if (err < 0)
1560                                 dev_dbg(&udev->dev, "HNP fail, %d\n", err);
1561                 }
1562                 err = -ENOTSUPP;
1563                 goto fail;
1564         }
1565 fail:
1566 #endif
1567         return err;
1568 }
1569
1570
1571 /**
1572  * usb_configure_device - Detect and probe device intfs/otg (usbcore-internal)
1573  * @udev: newly addressed device (in ADDRESS state)
1574  *
1575  * This is only called by usb_new_device() and usb_authorize_device()
1576  * and FIXME -- all comments that apply to them apply here wrt to
1577  * environment.
1578  *
1579  * If the device is WUSB and not authorized, we don't attempt to read
1580  * the string descriptors, as they will be errored out by the device
1581  * until it has been authorized.
1582  */
1583 static int usb_configure_device(struct usb_device *udev)
1584 {
1585         int err;
1586
1587         if (udev->config == NULL) {
1588                 err = usb_get_configuration(udev);
1589                 if (err < 0) {
1590                         dev_err(&udev->dev, "can't read configurations, error %d\n",
1591                                 err);
1592                         goto fail;
1593                 }
1594         }
1595         if (udev->wusb == 1 && udev->authorized == 0) {
1596                 udev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1597                 udev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1598                 udev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1599         }
1600         else {
1601                 /* read the standard strings and cache them if present */
1602                 udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
1603                 udev->manufacturer = usb_cache_string(udev,
1604                                                       udev->descriptor.iManufacturer);
1605                 udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
1606         }
1607         err = usb_configure_device_otg(udev);
1608 fail:
1609         return err;
1610 }
1611
1612
1613 /**
1614  * usb_new_device - perform initial device setup (usbcore-internal)
1615  * @udev: newly addressed device (in ADDRESS state)
1616  *
1617  * This is called with devices which have been enumerated, but not yet
1618  * configured.  The device descriptor is available, but not descriptors
1619  * for any device configuration.  The caller must have locked either
1620  * the parent hub (if udev is a normal device) or else the
1621  * usb_bus_list_lock (if udev is a root hub).  The parent's pointer to
1622  * udev has already been installed, but udev is not yet visible through
1623  * sysfs or other filesystem code.
1624  *
1625  * It will return if the device is configured properly or not.  Zero if
1626  * the interface was registered with the driver core; else a negative
1627  * errno value.
1628  *
1629  * This call is synchronous, and may not be used in an interrupt context.
1630  *
1631  * Only the hub driver or root-hub registrar should ever call this.
1632  */
1633 int usb_new_device(struct usb_device *udev)
1634 {
1635         int err;
1636
1637         /* Increment the parent's count of unsuspended children */
1638         if (udev->parent)
1639                 usb_autoresume_device(udev->parent);
1640
1641         usb_detect_quirks(udev);                /* Determine quirks */
1642         err = usb_configure_device(udev);       /* detect & probe dev/intfs */
1643         if (err < 0)
1644                 goto fail;
1645         /* export the usbdev device-node for libusb */
1646         udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
1647                         (((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
1648
1649         /* Tell the world! */
1650         announce_device(udev);
1651
1652         /* Register the device.  The device driver is responsible
1653          * for configuring the device and invoking the add-device
1654          * notifier chain (used by usbfs and possibly others).
1655          */
1656         err = device_add(&udev->dev);
1657         if (err) {
1658                 dev_err(&udev->dev, "can't device_add, error %d\n", err);
1659                 goto fail;
1660         }
1661
1662         (void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
1663         return err;
1664
1665 fail:
1666         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1667         usb_stop_pm(udev);
1668         return err;
1669 }
1670
1671
1672 /**
1673  * usb_deauthorize_device - deauthorize a device (usbcore-internal)
1674  * @usb_dev: USB device
1675  *
1676  * Move the USB device to a very basic state where interfaces are disabled
1677  * and the device is in fact unconfigured and unusable.
1678  *
1679  * We share a lock (that we have) with device_del(), so we need to
1680  * defer its call.
1681  */
1682 int usb_deauthorize_device(struct usb_device *usb_dev)
1683 {
1684         unsigned cnt;
1685         usb_lock_device(usb_dev);
1686         if (usb_dev->authorized == 0)
1687                 goto out_unauthorized;
1688         usb_dev->authorized = 0;
1689         usb_set_configuration(usb_dev, -1);
1690         usb_dev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1691         usb_dev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1692         usb_dev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1693         kfree(usb_dev->config);
1694         usb_dev->config = NULL;
1695         for (cnt = 0; cnt < usb_dev->descriptor.bNumConfigurations; cnt++)
1696                 kfree(usb_dev->rawdescriptors[cnt]);
1697         usb_dev->descriptor.bNumConfigurations = 0;
1698         kfree(usb_dev->rawdescriptors);
1699 out_unauthorized:
1700         usb_unlock_device(usb_dev);
1701         return 0;
1702 }
1703
1704
1705 int usb_authorize_device(struct usb_device *usb_dev)
1706 {
1707         int result = 0, c;
1708         usb_lock_device(usb_dev);
1709         if (usb_dev->authorized == 1)
1710                 goto out_authorized;
1711         kfree(usb_dev->product);
1712         usb_dev->product = NULL;
1713         kfree(usb_dev->manufacturer);
1714         usb_dev->manufacturer = NULL;
1715         kfree(usb_dev->serial);
1716         usb_dev->serial = NULL;
1717         result = usb_autoresume_device(usb_dev);
1718         if (result < 0) {
1719                 dev_err(&usb_dev->dev,
1720                         "can't autoresume for authorization: %d\n", result);
1721                 goto error_autoresume;
1722         }
1723         result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
1724         if (result < 0) {
1725                 dev_err(&usb_dev->dev, "can't re-read device descriptor for "
1726                         "authorization: %d\n", result);
1727                 goto error_device_descriptor;
1728         }
1729         usb_dev->authorized = 1;
1730         result = usb_configure_device(usb_dev);
1731         if (result < 0)
1732                 goto error_configure;
1733         /* Choose and set the configuration.  This registers the interfaces
1734          * with the driver core and lets interface drivers bind to them.
1735          */
1736         c = usb_choose_configuration(usb_dev);
1737         if (c >= 0) {
1738                 result = usb_set_configuration(usb_dev, c);
1739                 if (result) {
1740                         dev_err(&usb_dev->dev,
1741                                 "can't set config #%d, error %d\n", c, result);
1742                         /* This need not be fatal.  The user can try to
1743                          * set other configurations. */
1744                 }
1745         }
1746         dev_info(&usb_dev->dev, "authorized to connect\n");
1747 error_configure:
1748 error_device_descriptor:
1749 error_autoresume:
1750 out_authorized:
1751         usb_unlock_device(usb_dev);     // complements locktree
1752         return result;
1753 }
1754
1755
1756 /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
1757 static unsigned hub_is_wusb(struct usb_hub *hub)
1758 {
1759         struct usb_hcd *hcd;
1760         if (hub->hdev->parent != NULL)  /* not a root hub? */
1761                 return 0;
1762         hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
1763         return hcd->wireless;
1764 }
1765
1766
1767 #define PORT_RESET_TRIES        5
1768 #define SET_ADDRESS_TRIES       2
1769 #define GET_DESCRIPTOR_TRIES    2
1770 #define SET_CONFIG_TRIES        (2 * (use_both_schemes + 1))
1771 #define USE_NEW_SCHEME(i)       ((i) / 2 == old_scheme_first)
1772
1773 #define HUB_ROOT_RESET_TIME     50      /* times are in msec */
1774 #define HUB_SHORT_RESET_TIME    10
1775 #define HUB_LONG_RESET_TIME     200
1776 #define HUB_RESET_TIMEOUT       500
1777
1778 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
1779                                 struct usb_device *udev, unsigned int delay)
1780 {
1781         int delay_time, ret;
1782         u16 portstatus;
1783         u16 portchange;
1784
1785         for (delay_time = 0;
1786                         delay_time < HUB_RESET_TIMEOUT;
1787                         delay_time += delay) {
1788                 /* wait to give the device a chance to reset */
1789                 msleep(delay);
1790
1791                 /* read and decode port status */
1792                 ret = hub_port_status(hub, port1, &portstatus, &portchange);
1793                 if (ret < 0)
1794                         return ret;
1795
1796                 /* Device went away? */
1797                 if (!(portstatus & USB_PORT_STAT_CONNECTION))
1798                         return -ENOTCONN;
1799
1800                 /* bomb out completely if the connection bounced */
1801                 if ((portchange & USB_PORT_STAT_C_CONNECTION))
1802                         return -ENOTCONN;
1803
1804                 /* if we`ve finished resetting, then break out of the loop */
1805                 if (!(portstatus & USB_PORT_STAT_RESET) &&
1806                     (portstatus & USB_PORT_STAT_ENABLE)) {
1807                         if (hub_is_wusb(hub))
1808                                 udev->speed = USB_SPEED_VARIABLE;
1809                         else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
1810                                 udev->speed = USB_SPEED_HIGH;
1811                         else if (portstatus & USB_PORT_STAT_LOW_SPEED)
1812                                 udev->speed = USB_SPEED_LOW;
1813                         else
1814                                 udev->speed = USB_SPEED_FULL;
1815                         return 0;
1816                 }
1817
1818                 /* switch to the long delay after two short delay failures */
1819                 if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
1820                         delay = HUB_LONG_RESET_TIME;
1821
1822                 dev_dbg (hub->intfdev,
1823                         "port %d not reset yet, waiting %dms\n",
1824                         port1, delay);
1825         }
1826
1827         return -EBUSY;
1828 }
1829
1830 static int hub_port_reset(struct usb_hub *hub, int port1,
1831                                 struct usb_device *udev, unsigned int delay)
1832 {
1833         int i, status;
1834
1835         /* Block EHCI CF initialization during the port reset.
1836          * Some companion controllers don't like it when they mix.
1837          */
1838         down_read(&ehci_cf_port_reset_rwsem);
1839
1840         /* Reset the port */
1841         for (i = 0; i < PORT_RESET_TRIES; i++) {
1842                 status = set_port_feature(hub->hdev,
1843                                 port1, USB_PORT_FEAT_RESET);
1844                 if (status)
1845                         dev_err(hub->intfdev,
1846                                         "cannot reset port %d (err = %d)\n",
1847                                         port1, status);
1848                 else {
1849                         status = hub_port_wait_reset(hub, port1, udev, delay);
1850                         if (status && status != -ENOTCONN)
1851                                 dev_dbg(hub->intfdev,
1852                                                 "port_wait_reset: err = %d\n",
1853                                                 status);
1854                 }
1855
1856                 /* return on disconnect or reset */
1857                 switch (status) {
1858                 case 0:
1859                         /* TRSTRCY = 10 ms; plus some extra */
1860                         msleep(10 + 40);
1861                         update_address(udev, 0);
1862                         /* FALL THROUGH */
1863                 case -ENOTCONN:
1864                 case -ENODEV:
1865                         clear_port_feature(hub->hdev,
1866                                 port1, USB_PORT_FEAT_C_RESET);
1867                         /* FIXME need disconnect() for NOTATTACHED device */
1868                         usb_set_device_state(udev, status
1869                                         ? USB_STATE_NOTATTACHED
1870                                         : USB_STATE_DEFAULT);
1871                         goto done;
1872                 }
1873
1874                 dev_dbg (hub->intfdev,
1875                         "port %d not enabled, trying reset again...\n",
1876                         port1);
1877                 delay = HUB_LONG_RESET_TIME;
1878         }
1879
1880         dev_err (hub->intfdev,
1881                 "Cannot enable port %i.  Maybe the USB cable is bad?\n",
1882                 port1);
1883
1884  done:
1885         up_read(&ehci_cf_port_reset_rwsem);
1886         return status;
1887 }
1888
1889 #ifdef  CONFIG_PM
1890
1891 #define MASK_BITS       (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION | \
1892                                 USB_PORT_STAT_SUSPEND)
1893 #define WANT_BITS       (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION)
1894
1895 /* Determine whether the device on a port is ready for a normal resume,
1896  * is ready for a reset-resume, or should be disconnected.
1897  */
1898 static int check_port_resume_type(struct usb_device *udev,
1899                 struct usb_hub *hub, int port1,
1900                 int status, unsigned portchange, unsigned portstatus)
1901 {
1902         /* Is the device still present? */
1903         if (status || (portstatus & MASK_BITS) != WANT_BITS) {
1904                 if (status >= 0)
1905                         status = -ENODEV;
1906         }
1907
1908         /* Can't do a normal resume if the port isn't enabled,
1909          * so try a reset-resume instead.
1910          */
1911         else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) {
1912                 if (udev->persist_enabled)
1913                         udev->reset_resume = 1;
1914                 else
1915                         status = -ENODEV;
1916         }
1917
1918         if (status) {
1919                 dev_dbg(hub->intfdev,
1920                                 "port %d status %04x.%04x after resume, %d\n",
1921                                 port1, portchange, portstatus, status);
1922         } else if (udev->reset_resume) {
1923
1924                 /* Late port handoff can set status-change bits */
1925                 if (portchange & USB_PORT_STAT_C_CONNECTION)
1926                         clear_port_feature(hub->hdev, port1,
1927                                         USB_PORT_FEAT_C_CONNECTION);
1928                 if (portchange & USB_PORT_STAT_C_ENABLE)
1929                         clear_port_feature(hub->hdev, port1,
1930                                         USB_PORT_FEAT_C_ENABLE);
1931         }
1932
1933         return status;
1934 }
1935
1936 #ifdef  CONFIG_USB_SUSPEND
1937
1938 /*
1939  * usb_port_suspend - suspend a usb device's upstream port
1940  * @udev: device that's no longer in active use, not a root hub
1941  * Context: must be able to sleep; device not locked; pm locks held
1942  *
1943  * Suspends a USB device that isn't in active use, conserving power.
1944  * Devices may wake out of a suspend, if anything important happens,
1945  * using the remote wakeup mechanism.  They may also be taken out of
1946  * suspend by the host, using usb_port_resume().  It's also routine
1947  * to disconnect devices while they are suspended.
1948  *
1949  * This only affects the USB hardware for a device; its interfaces
1950  * (and, for hubs, child devices) must already have been suspended.
1951  *
1952  * Selective port suspend reduces power; most suspended devices draw
1953  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
1954  * All devices below the suspended port are also suspended.
1955  *
1956  * Devices leave suspend state when the host wakes them up.  Some devices
1957  * also support "remote wakeup", where the device can activate the USB
1958  * tree above them to deliver data, such as a keypress or packet.  In
1959  * some cases, this wakes the USB host.
1960  *
1961  * Suspending OTG devices may trigger HNP, if that's been enabled
1962  * between a pair of dual-role devices.  That will change roles, such
1963  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
1964  *
1965  * Devices on USB hub ports have only one "suspend" state, corresponding
1966  * to ACPI D2, "may cause the device to lose some context".
1967  * State transitions include:
1968  *
1969  *   - suspend, resume ... when the VBUS power link stays live
1970  *   - suspend, disconnect ... VBUS lost
1971  *
1972  * Once VBUS drop breaks the circuit, the port it's using has to go through
1973  * normal re-enumeration procedures, starting with enabling VBUS power.
1974  * Other than re-initializing the hub (plug/unplug, except for root hubs),
1975  * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
1976  * timer, no SRP, no requests through sysfs.
1977  *
1978  * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
1979  * the root hub for their bus goes into global suspend ... so we don't
1980  * (falsely) update the device power state to say it suspended.
1981  *
1982  * Returns 0 on success, else negative errno.
1983  */
1984 int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
1985 {
1986         struct usb_hub  *hub = hdev_to_hub(udev->parent);
1987         int             port1 = udev->portnum;
1988         int             status;
1989
1990         // dev_dbg(hub->intfdev, "suspend port %d\n", port1);
1991
1992         /* enable remote wakeup when appropriate; this lets the device
1993          * wake up the upstream hub (including maybe the root hub).
1994          *
1995          * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
1996          * we don't explicitly enable it here.
1997          */
1998         if (udev->do_remote_wakeup) {
1999                 status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2000                                 USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
2001                                 USB_DEVICE_REMOTE_WAKEUP, 0,
2002                                 NULL, 0,
2003                                 USB_CTRL_SET_TIMEOUT);
2004                 if (status)
2005                         dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
2006                                         status);
2007         }
2008
2009         /* see 7.1.7.6 */
2010         status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
2011         if (status) {
2012                 dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n",
2013                                 port1, status);
2014                 /* paranoia:  "should not happen" */
2015                 (void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2016                                 USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
2017                                 USB_DEVICE_REMOTE_WAKEUP, 0,
2018                                 NULL, 0,
2019                                 USB_CTRL_SET_TIMEOUT);
2020         } else {
2021                 /* device has up to 10 msec to fully suspend */
2022                 dev_dbg(&udev->dev, "usb %ssuspend\n",
2023                                 (msg.event & PM_EVENT_AUTO ? "auto-" : ""));
2024                 usb_set_device_state(udev, USB_STATE_SUSPENDED);
2025                 msleep(10);
2026         }
2027         return status;
2028 }
2029
2030 /*
2031  * If the USB "suspend" state is in use (rather than "global suspend"),
2032  * many devices will be individually taken out of suspend state using
2033  * special "resume" signaling.  This routine kicks in shortly after
2034  * hardware resume signaling is finished, either because of selective
2035  * resume (by host) or remote wakeup (by device) ... now see what changed
2036  * in the tree that's rooted at this device.
2037  *
2038  * If @udev->reset_resume is set then the device is reset before the
2039  * status check is done.
2040  */
2041 static int finish_port_resume(struct usb_device *udev)
2042 {
2043         int     status = 0;
2044         u16     devstatus;
2045
2046         /* caller owns the udev device lock */
2047         dev_dbg(&udev->dev, "%s\n",
2048                 udev->reset_resume ? "finish reset-resume" : "finish resume");
2049
2050         /* usb ch9 identifies four variants of SUSPENDED, based on what
2051          * state the device resumes to.  Linux currently won't see the
2052          * first two on the host side; they'd be inside hub_port_init()
2053          * during many timeouts, but khubd can't suspend until later.
2054          */
2055         usb_set_device_state(udev, udev->actconfig
2056                         ? USB_STATE_CONFIGURED
2057                         : USB_STATE_ADDRESS);
2058
2059         /* 10.5.4.5 says not to reset a suspended port if the attached
2060          * device is enabled for remote wakeup.  Hence the reset
2061          * operation is carried out here, after the port has been
2062          * resumed.
2063          */
2064         if (udev->reset_resume)
2065  retry_reset_resume:
2066                 status = usb_reset_and_verify_device(udev);
2067
2068         /* 10.5.4.5 says be sure devices in the tree are still there.
2069          * For now let's assume the device didn't go crazy on resume,
2070          * and device drivers will know about any resume quirks.
2071          */
2072         if (status == 0) {
2073                 devstatus = 0;
2074                 status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
2075                 if (status >= 0)
2076                         status = (status > 0 ? 0 : -ENODEV);
2077
2078                 /* If a normal resume failed, try doing a reset-resume */
2079                 if (status && !udev->reset_resume && udev->persist_enabled) {
2080                         dev_dbg(&udev->dev, "retry with reset-resume\n");
2081                         udev->reset_resume = 1;
2082                         goto retry_reset_resume;
2083                 }
2084         }
2085
2086         if (status) {
2087                 dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
2088                                 status);
2089         } else if (udev->actconfig) {
2090                 le16_to_cpus(&devstatus);
2091                 if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
2092                         status = usb_control_msg(udev,
2093                                         usb_sndctrlpipe(udev, 0),
2094                                         USB_REQ_CLEAR_FEATURE,
2095                                                 USB_RECIP_DEVICE,
2096                                         USB_DEVICE_REMOTE_WAKEUP, 0,
2097                                         NULL, 0,
2098                                         USB_CTRL_SET_TIMEOUT);
2099                         if (status)
2100                                 dev_dbg(&udev->dev,
2101                                         "disable remote wakeup, status %d\n",
2102                                         status);
2103                 }
2104                 status = 0;
2105         }
2106         return status;
2107 }
2108
2109 /*
2110  * usb_port_resume - re-activate a suspended usb device's upstream port
2111  * @udev: device to re-activate, not a root hub
2112  * Context: must be able to sleep; device not locked; pm locks held
2113  *
2114  * This will re-activate the suspended device, increasing power usage
2115  * while letting drivers communicate again with its endpoints.
2116  * USB resume explicitly guarantees that the power session between
2117  * the host and the device is the same as it was when the device
2118  * suspended.
2119  *
2120  * If @udev->reset_resume is set then this routine won't check that the
2121  * port is still enabled.  Furthermore, finish_port_resume() above will
2122  * reset @udev.  The end result is that a broken power session can be
2123  * recovered and @udev will appear to persist across a loss of VBUS power.
2124  *
2125  * For example, if a host controller doesn't maintain VBUS suspend current
2126  * during a system sleep or is reset when the system wakes up, all the USB
2127  * power sessions below it will be broken.  This is especially troublesome
2128  * for mass-storage devices containing mounted filesystems, since the
2129  * device will appear to have disconnected and all the memory mappings
2130  * to it will be lost.  Using the USB_PERSIST facility, the device can be
2131  * made to appear as if it had not disconnected.
2132  *
2133  * This facility can be dangerous.  Although usb_reset_and_verify_device() makes
2134  * every effort to insure that the same device is present after the
2135  * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
2136  * quite possible for a device to remain unaltered but its media to be
2137  * changed.  If the user replaces a flash memory card while the system is
2138  * asleep, he will have only himself to blame when the filesystem on the
2139  * new card is corrupted and the system crashes.
2140  *
2141  * Returns 0 on success, else negative errno.
2142  */
2143 int usb_port_resume(struct usb_device *udev, pm_message_t msg)
2144 {
2145         struct usb_hub  *hub = hdev_to_hub(udev->parent);
2146         int             port1 = udev->portnum;
2147         int             status;
2148         u16             portchange, portstatus;
2149
2150         /* Skip the initial Clear-Suspend step for a remote wakeup */
2151         status = hub_port_status(hub, port1, &portstatus, &portchange);
2152         if (status == 0 && !(portstatus & USB_PORT_STAT_SUSPEND))
2153                 goto SuspendCleared;
2154
2155         // dev_dbg(hub->intfdev, "resume port %d\n", port1);
2156
2157         set_bit(port1, hub->busy_bits);
2158
2159         /* see 7.1.7.7; affects power usage, but not budgeting */
2160         status = clear_port_feature(hub->hdev,
2161                         port1, USB_PORT_FEAT_SUSPEND);
2162         if (status) {
2163                 dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
2164                                 port1, status);
2165         } else {
2166                 /* drive resume for at least 20 msec */
2167                 dev_dbg(&udev->dev, "usb %sresume\n",
2168                                 (msg.event & PM_EVENT_AUTO ? "auto-" : ""));
2169                 msleep(25);
2170
2171                 /* Virtual root hubs can trigger on GET_PORT_STATUS to
2172                  * stop resume signaling.  Then finish the resume
2173                  * sequence.
2174                  */
2175                 status = hub_port_status(hub, port1, &portstatus, &portchange);
2176
2177                 /* TRSMRCY = 10 msec */
2178                 msleep(10);
2179         }
2180
2181  SuspendCleared:
2182         if (status == 0) {
2183                 if (portchange & USB_PORT_STAT_C_SUSPEND)
2184                         clear_port_feature(hub->hdev, port1,
2185                                         USB_PORT_FEAT_C_SUSPEND);
2186         }
2187
2188         clear_bit(port1, hub->busy_bits);
2189
2190         status = check_port_resume_type(udev,
2191                         hub, port1, status, portchange, portstatus);
2192         if (status == 0)
2193                 status = finish_port_resume(udev);
2194         if (status < 0) {
2195                 dev_dbg(&udev->dev, "can't resume, status %d\n", status);
2196                 hub_port_logical_disconnect(hub, port1);
2197         }
2198         return status;
2199 }
2200
2201 /* caller has locked udev */
2202 static int remote_wakeup(struct usb_device *udev)
2203 {
2204         int     status = 0;
2205
2206         if (udev->state == USB_STATE_SUSPENDED) {
2207                 dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
2208                 usb_mark_last_busy(udev);
2209                 status = usb_external_resume_device(udev, PMSG_REMOTE_RESUME);
2210         }
2211         return status;
2212 }
2213
2214 #else   /* CONFIG_USB_SUSPEND */
2215
2216 /* When CONFIG_USB_SUSPEND isn't set, we never suspend or resume any ports. */
2217
2218 int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
2219 {
2220         return 0;
2221 }
2222
2223 /* However we may need to do a reset-resume */
2224
2225 int usb_port_resume(struct usb_device *udev, pm_message_t msg)
2226 {
2227         struct usb_hub  *hub = hdev_to_hub(udev->parent);
2228         int             port1 = udev->portnum;
2229         int             status;
2230         u16             portchange, portstatus;
2231
2232         status = hub_port_status(hub, port1, &portstatus, &portchange);
2233         status = check_port_resume_type(udev,
2234                         hub, port1, status, portchange, portstatus);
2235
2236         if (status) {
2237                 dev_dbg(&udev->dev, "can't resume, status %d\n", status);
2238                 hub_port_logical_disconnect(hub, port1);
2239         } else if (udev->reset_resume) {
2240                 dev_dbg(&udev->dev, "reset-resume\n");
2241                 status = usb_reset_and_verify_device(udev);
2242         }
2243         return status;
2244 }
2245
2246 static inline int remote_wakeup(struct usb_device *udev)
2247 {
2248         return 0;
2249 }
2250
2251 #endif
2252
2253 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
2254 {
2255         struct usb_hub          *hub = usb_get_intfdata (intf);
2256         struct usb_device       *hdev = hub->hdev;
2257         unsigned                port1;
2258
2259         /* fail if children aren't already suspended */
2260         for (port1 = 1; port1 <= hdev->maxchild; port1++) {
2261                 struct usb_device       *udev;
2262
2263                 udev = hdev->children [port1-1];
2264                 if (udev && udev->can_submit) {
2265                         if (!(msg.event & PM_EVENT_AUTO))
2266                                 dev_dbg(&intf->dev, "port %d nyet suspended\n",
2267                                                 port1);
2268                         return -EBUSY;
2269                 }
2270         }
2271
2272         dev_dbg(&intf->dev, "%s\n", __func__);
2273
2274         /* stop khubd and related activity */
2275         hub_quiesce(hub, HUB_SUSPEND);
2276         return 0;
2277 }
2278
2279 static int hub_resume(struct usb_interface *intf)
2280 {
2281         struct usb_hub *hub = usb_get_intfdata(intf);
2282
2283         dev_dbg(&intf->dev, "%s\n", __func__);
2284         hub_activate(hub, HUB_RESUME);
2285         return 0;
2286 }
2287
2288 static int hub_reset_resume(struct usb_interface *intf)
2289 {
2290         struct usb_hub *hub = usb_get_intfdata(intf);
2291
2292         dev_dbg(&intf->dev, "%s\n", __func__);
2293         hub_activate(hub, HUB_RESET_RESUME);
2294         return 0;
2295 }
2296
2297 /**
2298  * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
2299  * @rhdev: struct usb_device for the root hub
2300  *
2301  * The USB host controller driver calls this function when its root hub
2302  * is resumed and Vbus power has been interrupted or the controller
2303  * has been reset.  The routine marks @rhdev as having lost power.
2304  * When the hub driver is resumed it will take notice and carry out
2305  * power-session recovery for all the "USB-PERSIST"-enabled child devices;
2306  * the others will be disconnected.
2307  */
2308 void usb_root_hub_lost_power(struct usb_device *rhdev)
2309 {
2310         dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
2311         rhdev->reset_resume = 1;
2312 }
2313 EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
2314
2315 #else   /* CONFIG_PM */
2316
2317 static inline int remote_wakeup(struct usb_device *udev)
2318 {
2319         return 0;
2320 }
2321
2322 #define hub_suspend             NULL
2323 #define hub_resume              NULL
2324 #define hub_reset_resume        NULL
2325 #endif
2326
2327
2328 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
2329  *
2330  * Between connect detection and reset signaling there must be a delay
2331  * of 100ms at least for debounce and power-settling.  The corresponding
2332  * timer shall restart whenever the downstream port detects a disconnect.
2333  * 
2334  * Apparently there are some bluetooth and irda-dongles and a number of
2335  * low-speed devices for which this debounce period may last over a second.
2336  * Not covered by the spec - but easy to deal with.
2337  *
2338  * This implementation uses a 1500ms total debounce timeout; if the
2339  * connection isn't stable by then it returns -ETIMEDOUT.  It checks
2340  * every 25ms for transient disconnects.  When the port status has been
2341  * unchanged for 100ms it returns the port status.
2342  */
2343 static int hub_port_debounce(struct usb_hub *hub, int port1)
2344 {
2345         int ret;
2346         int total_time, stable_time = 0;
2347         u16 portchange, portstatus;
2348         unsigned connection = 0xffff;
2349
2350         for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
2351                 ret = hub_port_status(hub, port1, &portstatus, &portchange);
2352                 if (ret < 0)
2353                         return ret;
2354
2355                 if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
2356                      (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
2357                         stable_time += HUB_DEBOUNCE_STEP;
2358                         if (stable_time >= HUB_DEBOUNCE_STABLE)
2359                                 break;
2360                 } else {
2361                         stable_time = 0;
2362                         connection = portstatus & USB_PORT_STAT_CONNECTION;
2363                 }
2364
2365                 if (portchange & USB_PORT_STAT_C_CONNECTION) {
2366                         clear_port_feature(hub->hdev, port1,
2367                                         USB_PORT_FEAT_C_CONNECTION);
2368                 }
2369
2370                 if (total_time >= HUB_DEBOUNCE_TIMEOUT)
2371                         break;
2372                 msleep(HUB_DEBOUNCE_STEP);
2373         }
2374
2375         dev_dbg (hub->intfdev,
2376                 "debounce: port %d: total %dms stable %dms status 0x%x\n",
2377                 port1, total_time, stable_time, portstatus);
2378
2379         if (stable_time < HUB_DEBOUNCE_STABLE)
2380                 return -ETIMEDOUT;
2381         return portstatus;
2382 }
2383
2384 void usb_ep0_reinit(struct usb_device *udev)
2385 {
2386         usb_disable_endpoint(udev, 0 + USB_DIR_IN, true);
2387         usb_disable_endpoint(udev, 0 + USB_DIR_OUT, true);
2388         usb_enable_endpoint(udev, &udev->ep0, true);
2389 }
2390 EXPORT_SYMBOL_GPL(usb_ep0_reinit);
2391
2392 #define usb_sndaddr0pipe()      (PIPE_CONTROL << 30)
2393 #define usb_rcvaddr0pipe()      ((PIPE_CONTROL << 30) | USB_DIR_IN)
2394
2395 static int hub_set_address(struct usb_device *udev, int devnum)
2396 {
2397         int retval;
2398
2399         if (devnum <= 1)
2400                 return -EINVAL;
2401         if (udev->state == USB_STATE_ADDRESS)
2402                 return 0;
2403         if (udev->state != USB_STATE_DEFAULT)
2404                 return -EINVAL;
2405         retval = usb_control_msg(udev, usb_sndaddr0pipe(),
2406                 USB_REQ_SET_ADDRESS, 0, devnum, 0,
2407                 NULL, 0, USB_CTRL_SET_TIMEOUT);
2408         if (retval == 0) {
2409                 /* Device now using proper address. */
2410                 update_address(udev, devnum);
2411                 usb_set_device_state(udev, USB_STATE_ADDRESS);
2412                 usb_ep0_reinit(udev);
2413         }
2414         return retval;
2415 }
2416
2417 /* Reset device, (re)assign address, get device descriptor.
2418  * Device connection must be stable, no more debouncing needed.
2419  * Returns device in USB_STATE_ADDRESS, except on error.
2420  *
2421  * If this is called for an already-existing device (as part of
2422  * usb_reset_and_verify_device), the caller must own the device lock.  For a
2423  * newly detected device that is not accessible through any global
2424  * pointers, it's not necessary to lock the device.
2425  */
2426 static int
2427 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
2428                 int retry_counter)
2429 {
2430         static DEFINE_MUTEX(usb_address0_mutex);
2431
2432         struct usb_device       *hdev = hub->hdev;
2433         int                     i, j, retval;
2434         unsigned                delay = HUB_SHORT_RESET_TIME;
2435         enum usb_device_speed   oldspeed = udev->speed;
2436         char                    *speed, *type;
2437         int                     devnum = udev->devnum;
2438
2439         /* root hub ports have a slightly longer reset period
2440          * (from USB 2.0 spec, section 7.1.7.5)
2441          */
2442         if (!hdev->parent) {
2443                 delay = HUB_ROOT_RESET_TIME;
2444                 if (port1 == hdev->bus->otg_port)
2445                         hdev->bus->b_hnp_enable = 0;
2446         }
2447
2448         /* Some low speed devices have problems with the quick delay, so */
2449         /*  be a bit pessimistic with those devices. RHbug #23670 */
2450         if (oldspeed == USB_SPEED_LOW)
2451                 delay = HUB_LONG_RESET_TIME;
2452
2453         mutex_lock(&usb_address0_mutex);
2454
2455         /* Reset the device; full speed may morph to high speed */
2456         retval = hub_port_reset(hub, port1, udev, delay);
2457         if (retval < 0)         /* error or disconnect */
2458                 goto fail;
2459                                 /* success, speed is known */
2460         retval = -ENODEV;
2461
2462         if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
2463                 dev_dbg(&udev->dev, "device reset changed speed!\n");
2464                 goto fail;
2465         }
2466         oldspeed = udev->speed;
2467
2468         /* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
2469          * it's fixed size except for full speed devices.
2470          * For Wireless USB devices, ep0 max packet is always 512 (tho
2471          * reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
2472          */
2473         switch (udev->speed) {
2474         case USB_SPEED_VARIABLE:        /* fixed at 512 */
2475                 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(512);
2476                 break;
2477         case USB_SPEED_HIGH:            /* fixed at 64 */
2478                 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
2479                 break;
2480         case USB_SPEED_FULL:            /* 8, 16, 32, or 64 */
2481                 /* to determine the ep0 maxpacket size, try to read
2482                  * the device descriptor to get bMaxPacketSize0 and
2483                  * then correct our initial guess.
2484                  */
2485                 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
2486                 break;
2487         case USB_SPEED_LOW:             /* fixed at 8 */
2488                 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(8);
2489                 break;
2490         default:
2491                 goto fail;
2492         }
2493  
2494         type = "";
2495         switch (udev->speed) {
2496         case USB_SPEED_LOW:     speed = "low";  break;
2497         case USB_SPEED_FULL:    speed = "full"; break;
2498         case USB_SPEED_HIGH:    speed = "high"; break;
2499         case USB_SPEED_VARIABLE:
2500                                 speed = "variable";
2501                                 type = "Wireless ";
2502                                 break;
2503         default:                speed = "?";    break;
2504         }
2505         dev_info (&udev->dev,
2506                   "%s %s speed %sUSB device using %s and address %d\n",
2507                   (udev->config) ? "reset" : "new", speed, type,
2508                   udev->bus->controller->driver->name, devnum);
2509
2510         /* Set up TT records, if needed  */
2511         if (hdev->tt) {
2512                 udev->tt = hdev->tt;
2513                 udev->ttport = hdev->ttport;
2514         } else if (udev->speed != USB_SPEED_HIGH
2515                         && hdev->speed == USB_SPEED_HIGH) {
2516                 udev->tt = &hub->tt;
2517                 udev->ttport = port1;
2518         }
2519  
2520         /* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
2521          * Because device hardware and firmware is sometimes buggy in
2522          * this area, and this is how Linux has done it for ages.
2523          * Change it cautiously.
2524          *
2525          * NOTE:  If USE_NEW_SCHEME() is true we will start by issuing
2526          * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
2527          * so it may help with some non-standards-compliant devices.
2528          * Otherwise we start with SET_ADDRESS and then try to read the
2529          * first 8 bytes of the device descriptor to get the ep0 maxpacket
2530          * value.
2531          */
2532         for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
2533                 if (USE_NEW_SCHEME(retry_counter)) {
2534                         struct usb_device_descriptor *buf;
2535                         int r = 0;
2536
2537 #define GET_DESCRIPTOR_BUFSIZE  64
2538                         buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
2539                         if (!buf) {
2540                                 retval = -ENOMEM;
2541                                 continue;
2542                         }
2543
2544                         /* Retry on all errors; some devices are flakey.
2545                          * 255 is for WUSB devices, we actually need to use
2546                          * 512 (WUSB1.0[4.8.1]).
2547                          */
2548                         for (j = 0; j < 3; ++j) {
2549                                 buf->bMaxPacketSize0 = 0;
2550                                 r = usb_control_msg(udev, usb_rcvaddr0pipe(),
2551                                         USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
2552                                         USB_DT_DEVICE << 8, 0,
2553                                         buf, GET_DESCRIPTOR_BUFSIZE,
2554                                         initial_descriptor_timeout);
2555                                 switch (buf->bMaxPacketSize0) {
2556                                 case 8: case 16: case 32: case 64: case 255:
2557                                         if (buf->bDescriptorType ==
2558                                                         USB_DT_DEVICE) {
2559                                                 r = 0;
2560                                                 break;
2561                                         }
2562                                         /* FALL THROUGH */
2563                                 default:
2564                                         if (r == 0)
2565                                                 r = -EPROTO;
2566                                         break;
2567                                 }
2568                                 if (r == 0)
2569                                         break;
2570                         }
2571                         udev->descriptor.bMaxPacketSize0 =
2572                                         buf->bMaxPacketSize0;
2573                         kfree(buf);
2574
2575                         retval = hub_port_reset(hub, port1, udev, delay);
2576                         if (retval < 0)         /* error or disconnect */
2577                                 goto fail;
2578                         if (oldspeed != udev->speed) {
2579                                 dev_dbg(&udev->dev,
2580                                         "device reset changed speed!\n");
2581                                 retval = -ENODEV;
2582                                 goto fail;
2583                         }
2584                         if (r) {
2585                                 dev_err(&udev->dev,
2586                                         "device descriptor read/64, error %d\n",
2587                                         r);
2588                                 retval = -EMSGSIZE;
2589                                 continue;
2590                         }
2591 #undef GET_DESCRIPTOR_BUFSIZE
2592                 }
2593
2594                 /*
2595                  * If device is WUSB, we already assigned an
2596                  * unauthorized address in the Connect Ack sequence;
2597                  * authorization will assign the final address.
2598                  */
2599                 if (udev->wusb == 0) {
2600                         for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
2601                                 retval = hub_set_address(udev, devnum);
2602                                 if (retval >= 0)
2603                                         break;
2604                                 msleep(200);
2605                         }
2606                         if (retval < 0) {
2607                                 dev_err(&udev->dev,
2608                                         "device not accepting address %d, error %d\n",
2609                                         devnum, retval);
2610                                 goto fail;
2611                         }
2612
2613                         /* cope with hardware quirkiness:
2614                          *  - let SET_ADDRESS settle, some device hardware wants it
2615                          *  - read ep0 maxpacket even for high and low speed,
2616                          */
2617                         msleep(10);
2618                         if (USE_NEW_SCHEME(retry_counter))
2619                                 break;
2620                 }
2621
2622                 retval = usb_get_device_descriptor(udev, 8);
2623                 if (retval < 8) {
2624                         dev_err(&udev->dev,
2625                                         "device descriptor read/8, error %d\n",
2626                                         retval);
2627                         if (retval >= 0)
2628                                 retval = -EMSGSIZE;
2629                 } else {
2630                         retval = 0;
2631                         break;
2632                 }
2633         }
2634         if (retval)
2635                 goto fail;
2636
2637         i = udev->descriptor.bMaxPacketSize0 == 0xff?   /* wusb device? */
2638             512 : udev->descriptor.bMaxPacketSize0;
2639         if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) {
2640                 if (udev->speed != USB_SPEED_FULL ||
2641                                 !(i == 8 || i == 16 || i == 32 || i == 64)) {
2642                         dev_err(&udev->dev, "ep0 maxpacket = %d\n", i);
2643                         retval = -EMSGSIZE;
2644                         goto fail;
2645                 }
2646                 dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
2647                 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
2648                 usb_ep0_reinit(udev);
2649         }
2650   
2651         retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
2652         if (retval < (signed)sizeof(udev->descriptor)) {
2653                 dev_err(&udev->dev, "device descriptor read/all, error %d\n",
2654                         retval);
2655                 if (retval >= 0)
2656                         retval = -ENOMSG;
2657                 goto fail;
2658         }
2659
2660         retval = 0;
2661
2662 fail:
2663         if (retval) {
2664                 hub_port_disable(hub, port1, 0);
2665                 update_address(udev, devnum);   /* for disconnect processing */
2666         }
2667         mutex_unlock(&usb_address0_mutex);
2668         return retval;
2669 }
2670
2671 static void
2672 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
2673 {
2674         struct usb_qualifier_descriptor *qual;
2675         int                             status;
2676
2677         qual = kmalloc (sizeof *qual, GFP_KERNEL);
2678         if (qual == NULL)
2679                 return;
2680
2681         status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
2682                         qual, sizeof *qual);
2683         if (status == sizeof *qual) {
2684                 dev_info(&udev->dev, "not running at top speed; "
2685                         "connect to a high speed hub\n");
2686                 /* hub LEDs are probably harder to miss than syslog */
2687                 if (hub->has_indicators) {
2688                         hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
2689                         schedule_delayed_work (&hub->leds, 0);
2690                 }
2691         }
2692         kfree(qual);
2693 }
2694
2695 static unsigned
2696 hub_power_remaining (struct usb_hub *hub)
2697 {
2698         struct usb_device *hdev = hub->hdev;
2699         int remaining;
2700         int port1;
2701
2702         if (!hub->limited_power)
2703                 return 0;
2704
2705         remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
2706         for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
2707                 struct usb_device       *udev = hdev->children[port1 - 1];
2708                 int                     delta;
2709
2710                 if (!udev)
2711                         continue;
2712
2713                 /* Unconfigured devices may not use more than 100mA,
2714                  * or 8mA for OTG ports */
2715                 if (udev->actconfig)
2716                         delta = udev->actconfig->desc.bMaxPower * 2;
2717                 else if (port1 != udev->bus->otg_port || hdev->parent)
2718                         delta = 100;
2719                 else
2720                         delta = 8;
2721                 if (delta > hub->mA_per_port)
2722                         dev_warn(&udev->dev,
2723                                  "%dmA is over %umA budget for port %d!\n",
2724                                  delta, hub->mA_per_port, port1);
2725                 remaining -= delta;
2726         }
2727         if (remaining < 0) {
2728                 dev_warn(hub->intfdev, "%dmA over power budget!\n",
2729                         - remaining);
2730                 remaining = 0;
2731         }
2732         return remaining;
2733 }
2734
2735 /* Handle physical or logical connection change events.
2736  * This routine is called when:
2737  *      a port connection-change occurs;
2738  *      a port enable-change occurs (often caused by EMI);
2739  *      usb_reset_and_verify_device() encounters changed descriptors (as from
2740  *              a firmware download)
2741  * caller already locked the hub
2742  */
2743 static void hub_port_connect_change(struct usb_hub *hub, int port1,
2744                                         u16 portstatus, u16 portchange)
2745 {
2746         struct usb_device *hdev = hub->hdev;
2747         struct device *hub_dev = hub->intfdev;
2748         struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
2749         unsigned wHubCharacteristics =
2750                         le16_to_cpu(hub->descriptor->wHubCharacteristics);
2751         struct usb_device *udev;
2752         int status, i;
2753
2754         dev_dbg (hub_dev,
2755                 "port %d, status %04x, change %04x, %s\n",
2756                 port1, portstatus, portchange, portspeed (portstatus));
2757
2758         if (hub->has_indicators) {
2759                 set_port_led(hub, port1, HUB_LED_AUTO);
2760                 hub->indicator[port1-1] = INDICATOR_AUTO;
2761         }
2762
2763 #ifdef  CONFIG_USB_OTG
2764         /* during HNP, don't repeat the debounce */
2765         if (hdev->bus->is_b_host)
2766                 portchange &= ~(USB_PORT_STAT_C_CONNECTION |
2767                                 USB_PORT_STAT_C_ENABLE);
2768 #endif
2769
2770         /* Try to resuscitate an existing device */
2771         udev = hdev->children[port1-1];
2772         if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
2773                         udev->state != USB_STATE_NOTATTACHED) {
2774                 usb_lock_device(udev);
2775                 if (portstatus & USB_PORT_STAT_ENABLE) {
2776                         status = 0;             /* Nothing to do */
2777
2778 #ifdef CONFIG_USB_SUSPEND
2779                 } else if (udev->state == USB_STATE_SUSPENDED &&
2780                                 udev->persist_enabled) {
2781                         /* For a suspended device, treat this as a
2782                          * remote wakeup event.
2783                          */
2784                         if (udev->do_remote_wakeup)
2785                                 status = remote_wakeup(udev);
2786
2787                         /* Otherwise leave it be; devices can't tell the
2788                          * difference between suspended and disabled.
2789                          */
2790                         else
2791                                 status = 0;
2792 #endif
2793
2794                 } else {
2795                         status = -ENODEV;       /* Don't resuscitate */
2796                 }
2797                 usb_unlock_device(udev);
2798
2799                 if (status == 0) {
2800                         clear_bit(port1, hub->change_bits);
2801                         return;
2802                 }
2803         }
2804
2805         /* Disconnect any existing devices under this port */
2806         if (udev)
2807                 usb_disconnect(&hdev->children[port1-1]);
2808         clear_bit(port1, hub->change_bits);
2809
2810         if (portchange & (USB_PORT_STAT_C_CONNECTION |
2811                                 USB_PORT_STAT_C_ENABLE)) {
2812                 status = hub_port_debounce(hub, port1);
2813                 if (status < 0) {
2814                         if (printk_ratelimit())
2815                                 dev_err(hub_dev, "connect-debounce failed, "
2816                                                 "port %d disabled\n", port1);
2817                         portstatus &= ~USB_PORT_STAT_CONNECTION;
2818                 } else {
2819                         portstatus = status;
2820                 }
2821         }
2822
2823         /* Return now if debouncing failed or nothing is connected */
2824         if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
2825
2826                 /* maybe switch power back on (e.g. root hub was reset) */
2827                 if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2
2828                                 && !(portstatus & (1 << USB_PORT_FEAT_POWER)))
2829                         set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
2830
2831                 if (portstatus & USB_PORT_STAT_ENABLE)
2832                         goto done;
2833                 return;
2834         }
2835
2836         for (i = 0; i < SET_CONFIG_TRIES; i++) {
2837
2838                 /* reallocate for each attempt, since references
2839                  * to the previous one can escape in various ways
2840                  */
2841                 udev = usb_alloc_dev(hdev, hdev->bus, port1);
2842                 if (!udev) {
2843                         dev_err (hub_dev,
2844                                 "couldn't allocate port %d usb_device\n",
2845                                 port1);
2846                         goto done;
2847                 }
2848
2849                 usb_set_device_state(udev, USB_STATE_POWERED);
2850                 udev->speed = USB_SPEED_UNKNOWN;
2851                 udev->bus_mA = hub->mA_per_port;
2852                 udev->level = hdev->level + 1;
2853                 udev->wusb = hub_is_wusb(hub);
2854
2855                 /* set the address */
2856                 choose_address(udev);
2857                 if (udev->devnum <= 0) {
2858                         status = -ENOTCONN;     /* Don't retry */
2859                         goto loop;
2860                 }
2861
2862                 /* reset and get descriptor */
2863                 status = hub_port_init(hub, udev, port1, i);
2864                 if (status < 0)
2865                         goto loop;
2866
2867                 /* consecutive bus-powered hubs aren't reliable; they can
2868                  * violate the voltage drop budget.  if the new child has
2869                  * a "powered" LED, users should notice we didn't enable it
2870                  * (without reading syslog), even without per-port LEDs
2871                  * on the parent.
2872                  */
2873                 if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
2874                                 && udev->bus_mA <= 100) {
2875                         u16     devstat;
2876
2877                         status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
2878                                         &devstat);
2879                         if (status < 2) {
2880                                 dev_dbg(&udev->dev, "get status %d ?\n", status);
2881                                 goto loop_disable;
2882                         }
2883                         le16_to_cpus(&devstat);
2884                         if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
2885                                 dev_err(&udev->dev,
2886                                         "can't connect bus-powered hub "
2887                                         "to this port\n");
2888                                 if (hub->has_indicators) {
2889                                         hub->indicator[port1-1] =
2890                                                 INDICATOR_AMBER_BLINK;
2891                                         schedule_delayed_work (&hub->leds, 0);
2892                                 }
2893                                 status = -ENOTCONN;     /* Don't retry */
2894                                 goto loop_disable;
2895                         }
2896                 }
2897  
2898                 /* check for devices running slower than they could */
2899                 if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
2900                                 && udev->speed == USB_SPEED_FULL
2901                                 && highspeed_hubs != 0)
2902                         check_highspeed (hub, udev, port1);
2903
2904                 /* Store the parent's children[] pointer.  At this point
2905                  * udev becomes globally accessible, although presumably
2906                  * no one will look at it until hdev is unlocked.
2907                  */
2908                 status = 0;
2909
2910                 /* We mustn't add new devices if the parent hub has
2911                  * been disconnected; we would race with the
2912                  * recursively_mark_NOTATTACHED() routine.
2913                  */
2914                 spin_lock_irq(&device_state_lock);
2915                 if (hdev->state == USB_STATE_NOTATTACHED)
2916                         status = -ENOTCONN;
2917                 else
2918                         hdev->children[port1-1] = udev;
2919                 spin_unlock_irq(&device_state_lock);
2920
2921                 /* Run it through the hoops (find a driver, etc) */
2922                 if (!status) {
2923                         status = usb_new_device(udev);
2924                         if (status) {
2925                                 spin_lock_irq(&device_state_lock);
2926                                 hdev->children[port1-1] = NULL;
2927                                 spin_unlock_irq(&device_state_lock);
2928                         }
2929                 }
2930
2931                 if (status)
2932                         goto loop_disable;
2933
2934                 status = hub_power_remaining(hub);
2935                 if (status)
2936                         dev_dbg(hub_dev, "%dmA power budget left\n", status);
2937
2938                 return;
2939
2940 loop_disable:
2941                 hub_port_disable(hub, port1, 1);
2942 loop:
2943                 usb_ep0_reinit(udev);
2944                 release_address(udev);
2945                 usb_put_dev(udev);
2946                 if ((status == -ENOTCONN) || (status == -ENOTSUPP))
2947                         break;
2948         }
2949         if (hub->hdev->parent ||
2950                         !hcd->driver->port_handed_over ||
2951                         !(hcd->driver->port_handed_over)(hcd, port1))
2952                 dev_err(hub_dev, "unable to enumerate USB device on port %d\n",
2953                                 port1);
2954  
2955 done:
2956         hub_port_disable(hub, port1, 1);
2957         if (hcd->driver->relinquish_port && !hub->hdev->parent)
2958                 hcd->driver->relinquish_port(hcd, port1);
2959 }
2960
2961 static void hub_events(void)
2962 {
2963         struct list_head *tmp;
2964         struct usb_device *hdev;
2965         struct usb_interface *intf;
2966         struct usb_hub *hub;
2967         struct device *hub_dev;
2968         u16 hubstatus;
2969         u16 hubchange;
2970         u16 portstatus;
2971         u16 portchange;
2972         int i, ret;
2973         int connect_change;
2974
2975         /*
2976          *  We restart the list every time to avoid a deadlock with
2977          * deleting hubs downstream from this one. This should be
2978          * safe since we delete the hub from the event list.
2979          * Not the most efficient, but avoids deadlocks.
2980          */
2981         while (1) {
2982
2983                 /* Grab the first entry at the beginning of the list */
2984                 spin_lock_irq(&hub_event_lock);
2985                 if (list_empty(&hub_event_list)) {
2986                         spin_unlock_irq(&hub_event_lock);
2987                         break;
2988                 }
2989
2990                 tmp = hub_event_list.next;
2991                 list_del_init(tmp);
2992
2993                 hub = list_entry(tmp, struct usb_hub, event_list);
2994                 kref_get(&hub->kref);
2995                 spin_unlock_irq(&hub_event_lock);
2996
2997                 hdev = hub->hdev;
2998                 hub_dev = hub->intfdev;
2999                 intf = to_usb_interface(hub_dev);
3000                 dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
3001                                 hdev->state, hub->descriptor
3002                                         ? hub->descriptor->bNbrPorts
3003                                         : 0,
3004                                 /* NOTE: expects max 15 ports... */
3005                                 (u16) hub->change_bits[0],
3006                                 (u16) hub->event_bits[0]);
3007
3008                 /* Lock the device, then check to see if we were
3009                  * disconnected while waiting for the lock to succeed. */
3010                 usb_lock_device(hdev);
3011                 if (unlikely(hub->disconnected))
3012                         goto loop;
3013
3014                 /* If the hub has died, clean up after it */
3015                 if (hdev->state == USB_STATE_NOTATTACHED) {
3016                         hub->error = -ENODEV;
3017                         hub_quiesce(hub, HUB_DISCONNECT);
3018                         goto loop;
3019                 }
3020
3021                 /* Autoresume */
3022                 ret = usb_autopm_get_interface(intf);
3023                 if (ret) {
3024                         dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
3025                         goto loop;
3026                 }
3027
3028                 /* If this is an inactive hub, do nothing */
3029                 if (hub->quiescing)
3030                         goto loop_autopm;
3031
3032                 if (hub->error) {
3033                         dev_dbg (hub_dev, "resetting for error %d\n",
3034                                 hub->error);
3035
3036                         ret = usb_reset_device(hdev);
3037                         if (ret) {
3038                                 dev_dbg (hub_dev,
3039                                         "error resetting hub: %d\n", ret);
3040                                 goto loop_autopm;
3041                         }
3042
3043                         hub->nerrors = 0;
3044                         hub->error = 0;
3045                 }
3046
3047                 /* deal with port status changes */
3048                 for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
3049                         if (test_bit(i, hub->busy_bits))
3050                                 continue;
3051                         connect_change = test_bit(i, hub->change_bits);
3052                         if (!test_and_clear_bit(i, hub->event_bits) &&
3053                                         !connect_change)
3054                                 continue;
3055
3056                         ret = hub_port_status(hub, i,
3057                                         &portstatus, &portchange);
3058                         if (ret < 0)
3059                                 continue;
3060
3061                         if (portchange & USB_PORT_STAT_C_CONNECTION) {
3062                                 clear_port_feature(hdev, i,
3063                                         USB_PORT_FEAT_C_CONNECTION);
3064                                 connect_change = 1;
3065                         }
3066
3067                         if (portchange & USB_PORT_STAT_C_ENABLE) {
3068                                 if (!connect_change)
3069                                         dev_dbg (hub_dev,
3070                                                 "port %d enable change, "
3071                                                 "status %08x\n",
3072                                                 i, portstatus);
3073                                 clear_port_feature(hdev, i,
3074                                         USB_PORT_FEAT_C_ENABLE);
3075
3076                                 /*
3077                                  * EM interference sometimes causes badly
3078                                  * shielded USB devices to be shutdown by
3079                                  * the hub, this hack enables them again.
3080                                  * Works at least with mouse driver. 
3081                                  */
3082                                 if (!(portstatus & USB_PORT_STAT_ENABLE)
3083                                     && !connect_change
3084                                     && hdev->children[i-1]) {
3085                                         dev_err (hub_dev,
3086                                             "port %i "
3087                                             "disabled by hub (EMI?), "
3088                                             "re-enabling...\n",
3089                                                 i);
3090                                         connect_change = 1;
3091                                 }
3092                         }
3093
3094                         if (portchange & USB_PORT_STAT_C_SUSPEND) {
3095                                 struct usb_device *udev;
3096
3097                                 clear_port_feature(hdev, i,
3098                                         USB_PORT_FEAT_C_SUSPEND);
3099                                 udev = hdev->children[i-1];
3100                                 if (udev) {
3101                                         usb_lock_device(udev);
3102                                         ret = remote_wakeup(hdev->
3103                                                         children[i-1]);
3104                                         usb_unlock_device(udev);
3105                                         if (ret < 0)
3106                                                 connect_change = 1;
3107                                 } else {
3108                                         ret = -ENODEV;
3109                                         hub_port_disable(hub, i, 1);
3110                                 }
3111                                 dev_dbg (hub_dev,
3112                                         "resume on port %d, status %d\n",
3113                                         i, ret);
3114                         }
3115                         
3116                         if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
3117                                 dev_err (hub_dev,
3118                                         "over-current change on port %d\n",
3119                                         i);
3120                                 clear_port_feature(hdev, i,
3121                                         USB_PORT_FEAT_C_OVER_CURRENT);
3122                                 hub_power_on(hub, true);
3123                         }
3124
3125                         if (portchange & USB_PORT_STAT_C_RESET) {
3126                                 dev_dbg (hub_dev,
3127                                         "reset change on port %d\n",
3128                                         i);
3129                                 clear_port_feature(hdev, i,
3130                                         USB_PORT_FEAT_C_RESET);
3131                         }
3132
3133                         if (connect_change)
3134                                 hub_port_connect_change(hub, i,
3135                                                 portstatus, portchange);
3136                 } /* end for i */
3137
3138                 /* deal with hub status changes */
3139                 if (test_and_clear_bit(0, hub->event_bits) == 0)
3140                         ;       /* do nothing */
3141                 else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
3142                         dev_err (hub_dev, "get_hub_status failed\n");
3143                 else {
3144                         if (hubchange & HUB_CHANGE_LOCAL_POWER) {
3145                                 dev_dbg (hub_dev, "power change\n");
3146                                 clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
3147                                 if (hubstatus & HUB_STATUS_LOCAL_POWER)
3148                                         /* FIXME: Is this always true? */
3149                                         hub->limited_power = 1;
3150                                 else
3151                                         hub->limited_power = 0;
3152                         }
3153                         if (hubchange & HUB_CHANGE_OVERCURRENT) {
3154                                 dev_dbg (hub_dev, "overcurrent change\n");
3155                                 msleep(500);    /* Cool down */
3156                                 clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
3157                                 hub_power_on(hub, true);
3158                         }
3159                 }
3160
3161 loop_autopm:
3162                 /* Allow autosuspend if we're not going to run again */
3163                 if (list_empty(&hub->event_list))
3164                         usb_autopm_enable(intf);
3165 loop:
3166                 usb_unlock_device(hdev);
3167                 kref_put(&hub->kref, hub_release);
3168
3169         } /* end while (1) */
3170 }
3171
3172 static int hub_thread(void *__unused)
3173 {
3174         /* khubd needs to be freezable to avoid intefering with USB-PERSIST
3175          * port handover.  Otherwise it might see that a full-speed device
3176          * was gone before the EHCI controller had handed its port over to
3177          * the companion full-speed controller.
3178          */
3179         set_freezable();
3180
3181         do {
3182                 hub_events();
3183                 wait_event_freezable(khubd_wait,
3184                                 !list_empty(&hub_event_list) ||
3185                                 kthread_should_stop());
3186         } while (!kthread_should_stop() || !list_empty(&hub_event_list));
3187
3188         pr_debug("%s: khubd exiting\n", usbcore_name);
3189         return 0;
3190 }
3191
3192 static struct usb_device_id hub_id_table [] = {
3193     { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
3194       .bDeviceClass = USB_CLASS_HUB},
3195     { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
3196       .bInterfaceClass = USB_CLASS_HUB},
3197     { }                                         /* Terminating entry */
3198 };
3199
3200 MODULE_DEVICE_TABLE (usb, hub_id_table);
3201
3202 static struct usb_driver hub_driver = {
3203         .name =         "hub",
3204         .probe =        hub_probe,
3205         .disconnect =   hub_disconnect,
3206         .suspend =      hub_suspend,
3207         .resume =       hub_resume,
3208         .reset_resume = hub_reset_resume,
3209         .pre_reset =    hub_pre_reset,
3210         .post_reset =   hub_post_reset,
3211         .ioctl =        hub_ioctl,
3212         .id_table =     hub_id_table,
3213         .supports_autosuspend = 1,
3214 };
3215
3216 int usb_hub_init(void)
3217 {
3218         if (usb_register(&hub_driver) < 0) {
3219                 printk(KERN_ERR "%s: can't register hub driver\n",
3220                         usbcore_name);
3221                 return -1;
3222         }
3223
3224         khubd_task = kthread_run(hub_thread, NULL, "khubd");
3225         if (!IS_ERR(khubd_task))
3226                 return 0;
3227
3228         /* Fall through if kernel_thread failed */
3229         usb_deregister(&hub_driver);
3230         printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
3231
3232         return -1;
3233 }
3234
3235 void usb_hub_cleanup(void)
3236 {
3237         kthread_stop(khubd_task);
3238
3239         /*
3240          * Hub resources are freed for us by usb_deregister. It calls
3241          * usb_driver_purge on every device which in turn calls that
3242          * devices disconnect function if it is using this driver.
3243          * The hub_disconnect function takes care of releasing the
3244          * individual hub resources. -greg
3245          */
3246         usb_deregister(&hub_driver);
3247 } /* usb_hub_cleanup() */
3248
3249 static int descriptors_changed(struct usb_device *udev,
3250                 struct usb_device_descriptor *old_device_descriptor)
3251 {
3252         int             changed = 0;
3253         unsigned        index;
3254         unsigned        serial_len = 0;
3255         unsigned        len;
3256         unsigned        old_length;
3257         int             length;
3258         char            *buf;
3259
3260         if (memcmp(&udev->descriptor, old_device_descriptor,
3261                         sizeof(*old_device_descriptor)) != 0)
3262                 return 1;
3263
3264         /* Since the idVendor, idProduct, and bcdDevice values in the
3265          * device descriptor haven't changed, we will assume the
3266          * Manufacturer and Product strings haven't changed either.
3267          * But the SerialNumber string could be different (e.g., a
3268          * different flash card of the same brand).
3269          */
3270         if (udev->serial)
3271                 serial_len = strlen(udev->serial) + 1;
3272
3273         len = serial_len;
3274         for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
3275                 old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
3276                 len = max(len, old_length);
3277         }
3278
3279         buf = kmalloc(len, GFP_NOIO);
3280         if (buf == NULL) {
3281                 dev_err(&udev->dev, "no mem to re-read configs after reset\n");
3282                 /* assume the worst */
3283                 return 1;
3284         }
3285         for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
3286                 old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
3287                 length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
3288                                 old_length);
3289                 if (length != old_length) {
3290                         dev_dbg(&udev->dev, "config index %d, error %d\n",
3291                                         index, length);
3292                         changed = 1;
3293                         break;
3294                 }
3295                 if (memcmp (buf, udev->rawdescriptors[index], old_length)
3296                                 != 0) {
3297                         dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
3298                                 index,
3299                                 ((struct usb_config_descriptor *) buf)->
3300                                         bConfigurationValue);
3301                         changed = 1;
3302                         break;
3303                 }
3304         }
3305
3306         if (!changed && serial_len) {
3307                 length = usb_string(udev, udev->descriptor.iSerialNumber,
3308                                 buf, serial_len);
3309                 if (length + 1 != serial_len) {
3310                         dev_dbg(&udev->dev, "serial string error %d\n",
3311                                         length);
3312                         changed = 1;
3313                 } else if (memcmp(buf, udev->serial, length) != 0) {
3314                         dev_dbg(&udev->dev, "serial string changed\n");
3315                         changed = 1;
3316                 }
3317         }
3318
3319         kfree(buf);
3320         return changed;
3321 }
3322
3323 /**
3324  * usb_reset_and_verify_device - perform a USB port reset to reinitialize a device
3325  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
3326  *
3327  * WARNING - don't use this routine to reset a composite device
3328  * (one with multiple interfaces owned by separate drivers)!
3329  * Use usb_reset_device() instead.
3330  *
3331  * Do a port reset, reassign the device's address, and establish its
3332  * former operating configuration.  If the reset fails, or the device's
3333  * descriptors change from their values before the reset, or the original
3334  * configuration and altsettings cannot be restored, a flag will be set
3335  * telling khubd to pretend the device has been disconnected and then
3336  * re-connected.  All drivers will be unbound, and the device will be
3337  * re-enumerated and probed all over again.
3338  *
3339  * Returns 0 if the reset succeeded, -ENODEV if the device has been
3340  * flagged for logical disconnection, or some other negative error code
3341  * if the reset wasn't even attempted.
3342  *
3343  * The caller must own the device lock.  For example, it's safe to use
3344  * this from a driver probe() routine after downloading new firmware.
3345  * For calls that might not occur during probe(), drivers should lock
3346  * the device using usb_lock_device_for_reset().
3347  *
3348  * Locking exception: This routine may also be called from within an
3349  * autoresume handler.  Such usage won't conflict with other tasks
3350  * holding the device lock because these tasks should always call
3351  * usb_autopm_resume_device(), thereby preventing any unwanted autoresume.
3352  */
3353 static int usb_reset_and_verify_device(struct usb_device *udev)
3354 {
3355         struct usb_device               *parent_hdev = udev->parent;
3356         struct usb_hub                  *parent_hub;
3357         struct usb_device_descriptor    descriptor = udev->descriptor;
3358         int                             i, ret = 0;
3359         int                             port1 = udev->portnum;
3360
3361         if (udev->state == USB_STATE_NOTATTACHED ||
3362                         udev->state == USB_STATE_SUSPENDED) {
3363                 dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
3364                                 udev->state);
3365                 return -EINVAL;
3366         }
3367
3368         if (!parent_hdev) {
3369                 /* this requires hcd-specific logic; see OHCI hc_restart() */
3370                 dev_dbg(&udev->dev, "%s for root hub!\n", __func__);
3371                 return -EISDIR;
3372         }
3373         parent_hub = hdev_to_hub(parent_hdev);
3374
3375         set_bit(port1, parent_hub->busy_bits);
3376         for (i = 0; i < SET_CONFIG_TRIES; ++i) {
3377
3378                 /* ep0 maxpacket size may change; let the HCD know about it.
3379                  * Other endpoints will be handled by re-enumeration. */
3380                 usb_ep0_reinit(udev);
3381                 ret = hub_port_init(parent_hub, udev, port1, i);
3382                 if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
3383                         break;
3384         }
3385         clear_bit(port1, parent_hub->busy_bits);
3386
3387         if (ret < 0)
3388                 goto re_enumerate;
3389  
3390         /* Device might have changed firmware (DFU or similar) */
3391         if (descriptors_changed(udev, &descriptor)) {
3392                 dev_info(&udev->dev, "device firmware changed\n");
3393                 udev->descriptor = descriptor;  /* for disconnect() calls */
3394                 goto re_enumerate;
3395         }
3396
3397         /* Restore the device's previous configuration */
3398         if (!udev->actconfig)
3399                 goto done;
3400         ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3401                         USB_REQ_SET_CONFIGURATION, 0,
3402                         udev->actconfig->desc.bConfigurationValue, 0,
3403                         NULL, 0, USB_CTRL_SET_TIMEOUT);
3404         if (ret < 0) {
3405                 dev_err(&udev->dev,
3406                         "can't restore configuration #%d (error=%d)\n",
3407                         udev->actconfig->desc.bConfigurationValue, ret);
3408                 goto re_enumerate;
3409         }
3410         usb_set_device_state(udev, USB_STATE_CONFIGURED);
3411
3412         /* Put interfaces back into the same altsettings as before.
3413          * Don't bother to send the Set-Interface request for interfaces
3414          * that were already in altsetting 0; besides being unnecessary,
3415          * many devices can't handle it.  Instead just reset the host-side
3416          * endpoint state.
3417          */
3418         for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
3419                 struct usb_interface *intf = udev->actconfig->interface[i];
3420                 struct usb_interface_descriptor *desc;
3421
3422                 desc = &intf->cur_altsetting->desc;
3423                 if (desc->bAlternateSetting == 0) {
3424                         usb_disable_interface(udev, intf, true);
3425                         usb_enable_interface(udev, intf, true);
3426                         ret = 0;
3427                 } else {
3428                         ret = usb_set_interface(udev, desc->bInterfaceNumber,
3429                                         desc->bAlternateSetting);
3430                 }
3431                 if (ret < 0) {
3432                         dev_err(&udev->dev, "failed to restore interface %d "
3433                                 "altsetting %d (error=%d)\n",
3434                                 desc->bInterfaceNumber,
3435                                 desc->bAlternateSetting,
3436                                 ret);
3437                         goto re_enumerate;
3438                 }
3439         }
3440
3441 done:
3442         return 0;
3443  
3444 re_enumerate:
3445         hub_port_logical_disconnect(parent_hub, port1);
3446         return -ENODEV;
3447 }
3448
3449 /**
3450  * usb_reset_device - warn interface drivers and perform a USB port reset
3451  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
3452  *
3453  * Warns all drivers bound to registered interfaces (using their pre_reset
3454  * method), performs the port reset, and then lets the drivers know that
3455  * the reset is over (using their post_reset method).
3456  *
3457  * Return value is the same as for usb_reset_and_verify_device().
3458  *
3459  * The caller must own the device lock.  For example, it's safe to use
3460  * this from a driver probe() routine after downloading new firmware.
3461  * For calls that might not occur during probe(), drivers should lock
3462  * the device using usb_lock_device_for_reset().
3463  *
3464  * If an interface is currently being probed or disconnected, we assume
3465  * its driver knows how to handle resets.  For all other interfaces,
3466  * if the driver doesn't have pre_reset and post_reset methods then
3467  * we attempt to unbind it and rebind afterward.
3468  */
3469 int usb_reset_device(struct usb_device *udev)
3470 {
3471         int ret;
3472         int i;
3473         struct usb_host_config *config = udev->actconfig;
3474
3475         if (udev->state == USB_STATE_NOTATTACHED ||
3476                         udev->state == USB_STATE_SUSPENDED) {
3477                 dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
3478                                 udev->state);
3479                 return -EINVAL;
3480         }
3481
3482         /* Prevent autosuspend during the reset */
3483         usb_autoresume_device(udev);
3484
3485         if (config) {
3486                 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
3487                         struct usb_interface *cintf = config->interface[i];
3488                         struct usb_driver *drv;
3489                         int unbind = 0;
3490
3491                         if (cintf->dev.driver) {
3492                                 drv = to_usb_driver(cintf->dev.driver);
3493                                 if (drv->pre_reset && drv->post_reset)
3494                                         unbind = (drv->pre_reset)(cintf);
3495                                 else if (cintf->condition ==
3496                                                 USB_INTERFACE_BOUND)
3497                                         unbind = 1;
3498                                 if (unbind)
3499                                         usb_forced_unbind_intf(cintf);
3500                         }
3501                 }
3502         }
3503
3504         ret = usb_reset_and_verify_device(udev);
3505
3506         if (config) {
3507                 for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
3508                         struct usb_interface *cintf = config->interface[i];
3509                         struct usb_driver *drv;
3510                         int rebind = cintf->needs_binding;
3511
3512                         if (!rebind && cintf->dev.driver) {
3513                                 drv = to_usb_driver(cintf->dev.driver);
3514                                 if (drv->post_reset)
3515                                         rebind = (drv->post_reset)(cintf);
3516                                 else if (cintf->condition ==
3517                                                 USB_INTERFACE_BOUND)
3518                                         rebind = 1;
3519                         }
3520                         if (ret == 0 && rebind)
3521                                 usb_rebind_intf(cintf);
3522                 }
3523         }
3524
3525         usb_autosuspend_device(udev);
3526         return ret;
3527 }
3528 EXPORT_SYMBOL_GPL(usb_reset_device);
3529
3530
3531 /**
3532  * usb_queue_reset_device - Reset a USB device from an atomic context
3533  * @iface: USB interface belonging to the device to reset
3534  *
3535  * This function can be used to reset a USB device from an atomic
3536  * context, where usb_reset_device() won't work (as it blocks).
3537  *
3538  * Doing a reset via this method is functionally equivalent to calling
3539  * usb_reset_device(), except for the fact that it is delayed to a
3540  * workqueue. This means that any drivers bound to other interfaces
3541  * might be unbound, as well as users from usbfs in user space.
3542  *
3543  * Corner cases:
3544  *
3545  * - Scheduling two resets at the same time from two different drivers
3546  *   attached to two different interfaces of the same device is
3547  *   possible; depending on how the driver attached to each interface
3548  *   handles ->pre_reset(), the second reset might happen or not.
3549  *
3550  * - If a driver is unbound and it had a pending reset, the reset will
3551  *   be cancelled.
3552  *
3553  * - This function can be called during .probe() or .disconnect()
3554  *   times. On return from .disconnect(), any pending resets will be
3555  *   cancelled.
3556  *
3557  * There is no no need to lock/unlock the @reset_ws as schedule_work()
3558  * does its own.
3559  *
3560  * NOTE: We don't do any reference count tracking because it is not
3561  *     needed. The lifecycle of the work_struct is tied to the
3562  *     usb_interface. Before destroying the interface we cancel the
3563  *     work_struct, so the fact that work_struct is queued and or
3564  *     running means the interface (and thus, the device) exist and
3565  *     are referenced.
3566  */
3567 void usb_queue_reset_device(struct usb_interface *iface)
3568 {
3569         schedule_work(&iface->reset_ws);
3570 }
3571 EXPORT_SYMBOL_GPL(usb_queue_reset_device);