Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
[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         int 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
1309 /*
1310  * WUSB devices are simple: they have no hubs behind, so the mapping
1311  * device <-> virtual port number becomes 1:1. Why? to simplify the
1312  * life of the device connection logic in
1313  * drivers/usb/wusbcore/devconnect.c. When we do the initial secret
1314  * handshake we need to assign a temporary address in the unauthorized
1315  * space. For simplicity we use the first virtual port number found to
1316  * be free [drivers/usb/wusbcore/devconnect.c:wusbhc_devconnect_ack()]
1317  * and that becomes it's address [X < 128] or its unauthorized address
1318  * [X | 0x80].
1319  *
1320  * We add 1 as an offset to the one-based USB-stack port number
1321  * (zero-based wusb virtual port index) for two reasons: (a) dev addr
1322  * 0 is reserved by USB for default address; (b) Linux's USB stack
1323  * uses always #1 for the root hub of the controller. So USB stack's
1324  * port #1, which is wusb virtual-port #0 has address #2.
1325  */
1326 static void choose_address(struct usb_device *udev)
1327 {
1328         int             devnum;
1329         struct usb_bus  *bus = udev->bus;
1330
1331         /* If khubd ever becomes multithreaded, this will need a lock */
1332         if (udev->wusb) {
1333                 devnum = udev->portnum + 1;
1334                 BUG_ON(test_bit(devnum, bus->devmap.devicemap));
1335         } else {
1336                 /* Try to allocate the next devnum beginning at
1337                  * bus->devnum_next. */
1338                 devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
1339                                             bus->devnum_next);
1340                 if (devnum >= 128)
1341                         devnum = find_next_zero_bit(bus->devmap.devicemap,
1342                                                     128, 1);
1343                 bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
1344         }
1345         if (devnum < 128) {
1346                 set_bit(devnum, bus->devmap.devicemap);
1347                 udev->devnum = devnum;
1348         }
1349 }
1350
1351 static void release_address(struct usb_device *udev)
1352 {
1353         if (udev->devnum > 0) {
1354                 clear_bit(udev->devnum, udev->bus->devmap.devicemap);
1355                 udev->devnum = -1;
1356         }
1357 }
1358
1359 static void update_address(struct usb_device *udev, int devnum)
1360 {
1361         /* The address for a WUSB device is managed by wusbcore. */
1362         if (!udev->wusb)
1363                 udev->devnum = devnum;
1364 }
1365
1366 #ifdef  CONFIG_USB_SUSPEND
1367
1368 static void usb_stop_pm(struct usb_device *udev)
1369 {
1370         /* Synchronize with the ksuspend thread to prevent any more
1371          * autosuspend requests from being submitted, and decrement
1372          * the parent's count of unsuspended children.
1373          */
1374         usb_pm_lock(udev);
1375         if (udev->parent && !udev->discon_suspended)
1376                 usb_autosuspend_device(udev->parent);
1377         usb_pm_unlock(udev);
1378
1379         /* Stop any autosuspend or autoresume requests already submitted */
1380         cancel_delayed_work_sync(&udev->autosuspend);
1381         cancel_work_sync(&udev->autoresume);
1382 }
1383
1384 #else
1385
1386 static inline void usb_stop_pm(struct usb_device *udev)
1387 { }
1388
1389 #endif
1390
1391 /**
1392  * usb_disconnect - disconnect a device (usbcore-internal)
1393  * @pdev: pointer to device being disconnected
1394  * Context: !in_interrupt ()
1395  *
1396  * Something got disconnected. Get rid of it and all of its children.
1397  *
1398  * If *pdev is a normal device then the parent hub must already be locked.
1399  * If *pdev is a root hub then this routine will acquire the
1400  * usb_bus_list_lock on behalf of the caller.
1401  *
1402  * Only hub drivers (including virtual root hub drivers for host
1403  * controllers) should ever call this.
1404  *
1405  * This call is synchronous, and may not be used in an interrupt context.
1406  */
1407 void usb_disconnect(struct usb_device **pdev)
1408 {
1409         struct usb_device       *udev = *pdev;
1410         int                     i;
1411
1412         if (!udev) {
1413                 pr_debug ("%s nodev\n", __func__);
1414                 return;
1415         }
1416
1417         /* mark the device as inactive, so any further urb submissions for
1418          * this device (and any of its children) will fail immediately.
1419          * this quiesces everyting except pending urbs.
1420          */
1421         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1422         dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum);
1423
1424         usb_lock_device(udev);
1425
1426         /* Free up all the children before we remove this device */
1427         for (i = 0; i < USB_MAXCHILDREN; i++) {
1428                 if (udev->children[i])
1429                         usb_disconnect(&udev->children[i]);
1430         }
1431
1432         /* deallocate hcd/hardware state ... nuking all pending urbs and
1433          * cleaning up all state associated with the current configuration
1434          * so that the hardware is now fully quiesced.
1435          */
1436         dev_dbg (&udev->dev, "unregistering device\n");
1437         usb_disable_device(udev, 0);
1438         usb_hcd_synchronize_unlinks(udev);
1439
1440         usb_remove_ep_devs(&udev->ep0);
1441         usb_unlock_device(udev);
1442
1443         /* Unregister the device.  The device driver is responsible
1444          * for de-configuring the device and invoking the remove-device
1445          * notifier chain (used by usbfs and possibly others).
1446          */
1447         device_del(&udev->dev);
1448
1449         /* Free the device number and delete the parent's children[]
1450          * (or root_hub) pointer.
1451          */
1452         release_address(udev);
1453
1454         /* Avoid races with recursively_mark_NOTATTACHED() */
1455         spin_lock_irq(&device_state_lock);
1456         *pdev = NULL;
1457         spin_unlock_irq(&device_state_lock);
1458
1459         usb_stop_pm(udev);
1460
1461         put_device(&udev->dev);
1462 }
1463
1464 #ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
1465 static void show_string(struct usb_device *udev, char *id, char *string)
1466 {
1467         if (!string)
1468                 return;
1469         dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string);
1470 }
1471
1472 static void announce_device(struct usb_device *udev)
1473 {
1474         dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n",
1475                 le16_to_cpu(udev->descriptor.idVendor),
1476                 le16_to_cpu(udev->descriptor.idProduct));
1477         dev_info(&udev->dev,
1478                 "New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
1479                 udev->descriptor.iManufacturer,
1480                 udev->descriptor.iProduct,
1481                 udev->descriptor.iSerialNumber);
1482         show_string(udev, "Product", udev->product);
1483         show_string(udev, "Manufacturer", udev->manufacturer);
1484         show_string(udev, "SerialNumber", udev->serial);
1485 }
1486 #else
1487 static inline void announce_device(struct usb_device *udev) { }
1488 #endif
1489
1490 #ifdef  CONFIG_USB_OTG
1491 #include "otg_whitelist.h"
1492 #endif
1493
1494 /**
1495  * usb_configure_device_otg - FIXME (usbcore-internal)
1496  * @udev: newly addressed device (in ADDRESS state)
1497  *
1498  * Do configuration for On-The-Go devices
1499  */
1500 static int usb_configure_device_otg(struct usb_device *udev)
1501 {
1502         int err = 0;
1503
1504 #ifdef  CONFIG_USB_OTG
1505         /*
1506          * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
1507          * to wake us after we've powered off VBUS; and HNP, switching roles
1508          * "host" to "peripheral".  The OTG descriptor helps figure this out.
1509          */
1510         if (!udev->bus->is_b_host
1511                         && udev->config
1512                         && udev->parent == udev->bus->root_hub) {
1513                 struct usb_otg_descriptor       *desc = 0;
1514                 struct usb_bus                  *bus = udev->bus;
1515
1516                 /* descriptor may appear anywhere in config */
1517                 if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
1518                                         le16_to_cpu(udev->config[0].desc.wTotalLength),
1519                                         USB_DT_OTG, (void **) &desc) == 0) {
1520                         if (desc->bmAttributes & USB_OTG_HNP) {
1521                                 unsigned                port1 = udev->portnum;
1522
1523                                 dev_info(&udev->dev,
1524                                         "Dual-Role OTG device on %sHNP port\n",
1525                                         (port1 == bus->otg_port)
1526                                                 ? "" : "non-");
1527
1528                                 /* enable HNP before suspend, it's simpler */
1529                                 if (port1 == bus->otg_port)
1530                                         bus->b_hnp_enable = 1;
1531                                 err = usb_control_msg(udev,
1532                                         usb_sndctrlpipe(udev, 0),
1533                                         USB_REQ_SET_FEATURE, 0,
1534                                         bus->b_hnp_enable
1535                                                 ? USB_DEVICE_B_HNP_ENABLE
1536                                                 : USB_DEVICE_A_ALT_HNP_SUPPORT,
1537                                         0, NULL, 0, USB_CTRL_SET_TIMEOUT);
1538                                 if (err < 0) {
1539                                         /* OTG MESSAGE: report errors here,
1540                                          * customize to match your product.
1541                                          */
1542                                         dev_info(&udev->dev,
1543                                                 "can't set HNP mode: %d\n",
1544                                                 err);
1545                                         bus->b_hnp_enable = 0;
1546                                 }
1547                         }
1548                 }
1549         }
1550
1551         if (!is_targeted(udev)) {
1552
1553                 /* Maybe it can talk to us, though we can't talk to it.
1554                  * (Includes HNP test device.)
1555                  */
1556                 if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
1557                         err = usb_port_suspend(udev);
1558                         if (err < 0)
1559                                 dev_dbg(&udev->dev, "HNP fail, %d\n", err);
1560                 }
1561                 err = -ENOTSUPP;
1562                 goto fail;
1563         }
1564 fail:
1565 #endif
1566         return err;
1567 }
1568
1569
1570 /**
1571  * usb_configure_device - Detect and probe device intfs/otg (usbcore-internal)
1572  * @udev: newly addressed device (in ADDRESS state)
1573  *
1574  * This is only called by usb_new_device() and usb_authorize_device()
1575  * and FIXME -- all comments that apply to them apply here wrt to
1576  * environment.
1577  *
1578  * If the device is WUSB and not authorized, we don't attempt to read
1579  * the string descriptors, as they will be errored out by the device
1580  * until it has been authorized.
1581  */
1582 static int usb_configure_device(struct usb_device *udev)
1583 {
1584         int err;
1585
1586         if (udev->config == NULL) {
1587                 err = usb_get_configuration(udev);
1588                 if (err < 0) {
1589                         dev_err(&udev->dev, "can't read configurations, error %d\n",
1590                                 err);
1591                         goto fail;
1592                 }
1593         }
1594         if (udev->wusb == 1 && udev->authorized == 0) {
1595                 udev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1596                 udev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1597                 udev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1598         }
1599         else {
1600                 /* read the standard strings and cache them if present */
1601                 udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
1602                 udev->manufacturer = usb_cache_string(udev,
1603                                                       udev->descriptor.iManufacturer);
1604                 udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
1605         }
1606         err = usb_configure_device_otg(udev);
1607 fail:
1608         return err;
1609 }
1610
1611
1612 /**
1613  * usb_new_device - perform initial device setup (usbcore-internal)
1614  * @udev: newly addressed device (in ADDRESS state)
1615  *
1616  * This is called with devices which have been enumerated, but not yet
1617  * configured.  The device descriptor is available, but not descriptors
1618  * for any device configuration.  The caller must have locked either
1619  * the parent hub (if udev is a normal device) or else the
1620  * usb_bus_list_lock (if udev is a root hub).  The parent's pointer to
1621  * udev has already been installed, but udev is not yet visible through
1622  * sysfs or other filesystem code.
1623  *
1624  * It will return if the device is configured properly or not.  Zero if
1625  * the interface was registered with the driver core; else a negative
1626  * errno value.
1627  *
1628  * This call is synchronous, and may not be used in an interrupt context.
1629  *
1630  * Only the hub driver or root-hub registrar should ever call this.
1631  */
1632 int usb_new_device(struct usb_device *udev)
1633 {
1634         int err;
1635
1636         /* Increment the parent's count of unsuspended children */
1637         if (udev->parent)
1638                 usb_autoresume_device(udev->parent);
1639
1640         usb_detect_quirks(udev);                /* Determine quirks */
1641         err = usb_configure_device(udev);       /* detect & probe dev/intfs */
1642         if (err < 0)
1643                 goto fail;
1644         /* export the usbdev device-node for libusb */
1645         udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
1646                         (((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
1647
1648         /* Tell the world! */
1649         announce_device(udev);
1650
1651         /* Register the device.  The device driver is responsible
1652          * for configuring the device and invoking the add-device
1653          * notifier chain (used by usbfs and possibly others).
1654          */
1655         err = device_add(&udev->dev);
1656         if (err) {
1657                 dev_err(&udev->dev, "can't device_add, error %d\n", err);
1658                 goto fail;
1659         }
1660
1661         (void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
1662         return err;
1663
1664 fail:
1665         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1666         usb_stop_pm(udev);
1667         return err;
1668 }
1669
1670
1671 /**
1672  * usb_deauthorize_device - deauthorize a device (usbcore-internal)
1673  * @usb_dev: USB device
1674  *
1675  * Move the USB device to a very basic state where interfaces are disabled
1676  * and the device is in fact unconfigured and unusable.
1677  *
1678  * We share a lock (that we have) with device_del(), so we need to
1679  * defer its call.
1680  */
1681 int usb_deauthorize_device(struct usb_device *usb_dev)
1682 {
1683         unsigned cnt;
1684         usb_lock_device(usb_dev);
1685         if (usb_dev->authorized == 0)
1686                 goto out_unauthorized;
1687         usb_dev->authorized = 0;
1688         usb_set_configuration(usb_dev, -1);
1689         usb_dev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1690         usb_dev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1691         usb_dev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
1692         kfree(usb_dev->config);
1693         usb_dev->config = NULL;
1694         for (cnt = 0; cnt < usb_dev->descriptor.bNumConfigurations; cnt++)
1695                 kfree(usb_dev->rawdescriptors[cnt]);
1696         usb_dev->descriptor.bNumConfigurations = 0;
1697         kfree(usb_dev->rawdescriptors);
1698 out_unauthorized:
1699         usb_unlock_device(usb_dev);
1700         return 0;
1701 }
1702
1703
1704 int usb_authorize_device(struct usb_device *usb_dev)
1705 {
1706         int result = 0, c;
1707         usb_lock_device(usb_dev);
1708         if (usb_dev->authorized == 1)
1709                 goto out_authorized;
1710         kfree(usb_dev->product);
1711         usb_dev->product = NULL;
1712         kfree(usb_dev->manufacturer);
1713         usb_dev->manufacturer = NULL;
1714         kfree(usb_dev->serial);
1715         usb_dev->serial = NULL;
1716         result = usb_autoresume_device(usb_dev);
1717         if (result < 0) {
1718                 dev_err(&usb_dev->dev,
1719                         "can't autoresume for authorization: %d\n", result);
1720                 goto error_autoresume;
1721         }
1722         result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
1723         if (result < 0) {
1724                 dev_err(&usb_dev->dev, "can't re-read device descriptor for "
1725                         "authorization: %d\n", result);
1726                 goto error_device_descriptor;
1727         }
1728         usb_dev->authorized = 1;
1729         result = usb_configure_device(usb_dev);
1730         if (result < 0)
1731                 goto error_configure;
1732         /* Choose and set the configuration.  This registers the interfaces
1733          * with the driver core and lets interface drivers bind to them.
1734          */
1735         c = usb_choose_configuration(usb_dev);
1736         if (c >= 0) {
1737                 result = usb_set_configuration(usb_dev, c);
1738                 if (result) {
1739                         dev_err(&usb_dev->dev,
1740                                 "can't set config #%d, error %d\n", c, result);
1741                         /* This need not be fatal.  The user can try to
1742                          * set other configurations. */
1743                 }
1744         }
1745         dev_info(&usb_dev->dev, "authorized to connect\n");
1746 error_configure:
1747 error_device_descriptor:
1748 error_autoresume:
1749 out_authorized:
1750         usb_unlock_device(usb_dev);     // complements locktree
1751         return result;
1752 }
1753
1754
1755 /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
1756 static unsigned hub_is_wusb(struct usb_hub *hub)
1757 {
1758         struct usb_hcd *hcd;
1759         if (hub->hdev->parent != NULL)  /* not a root hub? */
1760                 return 0;
1761         hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
1762         return hcd->wireless;
1763 }
1764
1765
1766 #define PORT_RESET_TRIES        5
1767 #define SET_ADDRESS_TRIES       2
1768 #define GET_DESCRIPTOR_TRIES    2
1769 #define SET_CONFIG_TRIES        (2 * (use_both_schemes + 1))
1770 #define USE_NEW_SCHEME(i)       ((i) / 2 == old_scheme_first)
1771
1772 #define HUB_ROOT_RESET_TIME     50      /* times are in msec */
1773 #define HUB_SHORT_RESET_TIME    10
1774 #define HUB_LONG_RESET_TIME     200
1775 #define HUB_RESET_TIMEOUT       500
1776
1777 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
1778                                 struct usb_device *udev, unsigned int delay)
1779 {
1780         int delay_time, ret;
1781         u16 portstatus;
1782         u16 portchange;
1783
1784         for (delay_time = 0;
1785                         delay_time < HUB_RESET_TIMEOUT;
1786                         delay_time += delay) {
1787                 /* wait to give the device a chance to reset */
1788                 msleep(delay);
1789
1790                 /* read and decode port status */
1791                 ret = hub_port_status(hub, port1, &portstatus, &portchange);
1792                 if (ret < 0)
1793                         return ret;
1794
1795                 /* Device went away? */
1796                 if (!(portstatus & USB_PORT_STAT_CONNECTION))
1797                         return -ENOTCONN;
1798
1799                 /* bomb out completely if the connection bounced */
1800                 if ((portchange & USB_PORT_STAT_C_CONNECTION))
1801                         return -ENOTCONN;
1802
1803                 /* if we`ve finished resetting, then break out of the loop */
1804                 if (!(portstatus & USB_PORT_STAT_RESET) &&
1805                     (portstatus & USB_PORT_STAT_ENABLE)) {
1806                         if (hub_is_wusb(hub))
1807                                 udev->speed = USB_SPEED_VARIABLE;
1808                         else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
1809                                 udev->speed = USB_SPEED_HIGH;
1810                         else if (portstatus & USB_PORT_STAT_LOW_SPEED)
1811                                 udev->speed = USB_SPEED_LOW;
1812                         else
1813                                 udev->speed = USB_SPEED_FULL;
1814                         return 0;
1815                 }
1816
1817                 /* switch to the long delay after two short delay failures */
1818                 if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
1819                         delay = HUB_LONG_RESET_TIME;
1820
1821                 dev_dbg (hub->intfdev,
1822                         "port %d not reset yet, waiting %dms\n",
1823                         port1, delay);
1824         }
1825
1826         return -EBUSY;
1827 }
1828
1829 static int hub_port_reset(struct usb_hub *hub, int port1,
1830                                 struct usb_device *udev, unsigned int delay)
1831 {
1832         int i, status;
1833
1834         /* Block EHCI CF initialization during the port reset.
1835          * Some companion controllers don't like it when they mix.
1836          */
1837         down_read(&ehci_cf_port_reset_rwsem);
1838
1839         /* Reset the port */
1840         for (i = 0; i < PORT_RESET_TRIES; i++) {
1841                 status = set_port_feature(hub->hdev,
1842                                 port1, USB_PORT_FEAT_RESET);
1843                 if (status)
1844                         dev_err(hub->intfdev,
1845                                         "cannot reset port %d (err = %d)\n",
1846                                         port1, status);
1847                 else {
1848                         status = hub_port_wait_reset(hub, port1, udev, delay);
1849                         if (status && status != -ENOTCONN)
1850                                 dev_dbg(hub->intfdev,
1851                                                 "port_wait_reset: err = %d\n",
1852                                                 status);
1853                 }
1854
1855                 /* return on disconnect or reset */
1856                 switch (status) {
1857                 case 0:
1858                         /* TRSTRCY = 10 ms; plus some extra */
1859                         msleep(10 + 40);
1860                         update_address(udev, 0);
1861                         /* FALL THROUGH */
1862                 case -ENOTCONN:
1863                 case -ENODEV:
1864                         clear_port_feature(hub->hdev,
1865                                 port1, USB_PORT_FEAT_C_RESET);
1866                         /* FIXME need disconnect() for NOTATTACHED device */
1867                         usb_set_device_state(udev, status
1868                                         ? USB_STATE_NOTATTACHED
1869                                         : USB_STATE_DEFAULT);
1870                         goto done;
1871                 }
1872
1873                 dev_dbg (hub->intfdev,
1874                         "port %d not enabled, trying reset again...\n",
1875                         port1);
1876                 delay = HUB_LONG_RESET_TIME;
1877         }
1878
1879         dev_err (hub->intfdev,
1880                 "Cannot enable port %i.  Maybe the USB cable is bad?\n",
1881                 port1);
1882
1883  done:
1884         up_read(&ehci_cf_port_reset_rwsem);
1885         return status;
1886 }
1887
1888 #ifdef  CONFIG_PM
1889
1890 #define MASK_BITS       (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION | \
1891                                 USB_PORT_STAT_SUSPEND)
1892 #define WANT_BITS       (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION)
1893
1894 /* Determine whether the device on a port is ready for a normal resume,
1895  * is ready for a reset-resume, or should be disconnected.
1896  */
1897 static int check_port_resume_type(struct usb_device *udev,
1898                 struct usb_hub *hub, int port1,
1899                 int status, unsigned portchange, unsigned portstatus)
1900 {
1901         /* Is the device still present? */
1902         if (status || (portstatus & MASK_BITS) != WANT_BITS) {
1903                 if (status >= 0)
1904                         status = -ENODEV;
1905         }
1906
1907         /* Can't do a normal resume if the port isn't enabled,
1908          * so try a reset-resume instead.
1909          */
1910         else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) {
1911                 if (udev->persist_enabled)
1912                         udev->reset_resume = 1;
1913                 else
1914                         status = -ENODEV;
1915         }
1916
1917         if (status) {
1918                 dev_dbg(hub->intfdev,
1919                                 "port %d status %04x.%04x after resume, %d\n",
1920                                 port1, portchange, portstatus, status);
1921         } else if (udev->reset_resume) {
1922
1923                 /* Late port handoff can set status-change bits */
1924                 if (portchange & USB_PORT_STAT_C_CONNECTION)
1925                         clear_port_feature(hub->hdev, port1,
1926                                         USB_PORT_FEAT_C_CONNECTION);
1927                 if (portchange & USB_PORT_STAT_C_ENABLE)
1928                         clear_port_feature(hub->hdev, port1,
1929                                         USB_PORT_FEAT_C_ENABLE);
1930         }
1931
1932         return status;
1933 }
1934
1935 #ifdef  CONFIG_USB_SUSPEND
1936
1937 /*
1938  * usb_port_suspend - suspend a usb device's upstream port
1939  * @udev: device that's no longer in active use, not a root hub
1940  * Context: must be able to sleep; device not locked; pm locks held
1941  *
1942  * Suspends a USB device that isn't in active use, conserving power.
1943  * Devices may wake out of a suspend, if anything important happens,
1944  * using the remote wakeup mechanism.  They may also be taken out of
1945  * suspend by the host, using usb_port_resume().  It's also routine
1946  * to disconnect devices while they are suspended.
1947  *
1948  * This only affects the USB hardware for a device; its interfaces
1949  * (and, for hubs, child devices) must already have been suspended.
1950  *
1951  * Selective port suspend reduces power; most suspended devices draw
1952  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
1953  * All devices below the suspended port are also suspended.
1954  *
1955  * Devices leave suspend state when the host wakes them up.  Some devices
1956  * also support "remote wakeup", where the device can activate the USB
1957  * tree above them to deliver data, such as a keypress or packet.  In
1958  * some cases, this wakes the USB host.
1959  *
1960  * Suspending OTG devices may trigger HNP, if that's been enabled
1961  * between a pair of dual-role devices.  That will change roles, such
1962  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
1963  *
1964  * Devices on USB hub ports have only one "suspend" state, corresponding
1965  * to ACPI D2, "may cause the device to lose some context".
1966  * State transitions include:
1967  *
1968  *   - suspend, resume ... when the VBUS power link stays live
1969  *   - suspend, disconnect ... VBUS lost
1970  *
1971  * Once VBUS drop breaks the circuit, the port it's using has to go through
1972  * normal re-enumeration procedures, starting with enabling VBUS power.
1973  * Other than re-initializing the hub (plug/unplug, except for root hubs),
1974  * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
1975  * timer, no SRP, no requests through sysfs.
1976  *
1977  * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
1978  * the root hub for their bus goes into global suspend ... so we don't
1979  * (falsely) update the device power state to say it suspended.
1980  *
1981  * Returns 0 on success, else negative errno.
1982  */
1983 int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
1984 {
1985         struct usb_hub  *hub = hdev_to_hub(udev->parent);
1986         int             port1 = udev->portnum;
1987         int             status;
1988
1989         // dev_dbg(hub->intfdev, "suspend port %d\n", port1);
1990
1991         /* enable remote wakeup when appropriate; this lets the device
1992          * wake up the upstream hub (including maybe the root hub).
1993          *
1994          * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
1995          * we don't explicitly enable it here.
1996          */
1997         if (udev->do_remote_wakeup) {
1998                 status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1999                                 USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
2000                                 USB_DEVICE_REMOTE_WAKEUP, 0,
2001                                 NULL, 0,
2002                                 USB_CTRL_SET_TIMEOUT);
2003                 if (status)
2004                         dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
2005                                         status);
2006         }
2007
2008         /* see 7.1.7.6 */
2009         status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
2010         if (status) {
2011                 dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n",
2012                                 port1, status);
2013                 /* paranoia:  "should not happen" */
2014                 (void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2015                                 USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
2016                                 USB_DEVICE_REMOTE_WAKEUP, 0,
2017                                 NULL, 0,
2018                                 USB_CTRL_SET_TIMEOUT);
2019         } else {
2020                 /* device has up to 10 msec to fully suspend */
2021                 dev_dbg(&udev->dev, "usb %ssuspend\n",
2022                                 (msg.event & PM_EVENT_AUTO ? "auto-" : ""));
2023                 usb_set_device_state(udev, USB_STATE_SUSPENDED);
2024                 msleep(10);
2025         }
2026         return status;
2027 }
2028
2029 /*
2030  * If the USB "suspend" state is in use (rather than "global suspend"),
2031  * many devices will be individually taken out of suspend state using
2032  * special "resume" signaling.  This routine kicks in shortly after
2033  * hardware resume signaling is finished, either because of selective
2034  * resume (by host) or remote wakeup (by device) ... now see what changed
2035  * in the tree that's rooted at this device.
2036  *
2037  * If @udev->reset_resume is set then the device is reset before the
2038  * status check is done.
2039  */
2040 static int finish_port_resume(struct usb_device *udev)
2041 {
2042         int     status = 0;
2043         u16     devstatus;
2044
2045         /* caller owns the udev device lock */
2046         dev_dbg(&udev->dev, "%s\n",
2047                 udev->reset_resume ? "finish reset-resume" : "finish resume");
2048
2049         /* usb ch9 identifies four variants of SUSPENDED, based on what
2050          * state the device resumes to.  Linux currently won't see the
2051          * first two on the host side; they'd be inside hub_port_init()
2052          * during many timeouts, but khubd can't suspend until later.
2053          */
2054         usb_set_device_state(udev, udev->actconfig
2055                         ? USB_STATE_CONFIGURED
2056                         : USB_STATE_ADDRESS);
2057
2058         /* 10.5.4.5 says not to reset a suspended port if the attached
2059          * device is enabled for remote wakeup.  Hence the reset
2060          * operation is carried out here, after the port has been
2061          * resumed.
2062          */
2063         if (udev->reset_resume)
2064  retry_reset_resume:
2065                 status = usb_reset_and_verify_device(udev);
2066
2067         /* 10.5.4.5 says be sure devices in the tree are still there.
2068          * For now let's assume the device didn't go crazy on resume,
2069          * and device drivers will know about any resume quirks.
2070          */
2071         if (status == 0) {
2072                 devstatus = 0;
2073                 status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
2074                 if (status >= 0)
2075                         status = (status > 0 ? 0 : -ENODEV);
2076
2077                 /* If a normal resume failed, try doing a reset-resume */
2078                 if (status && !udev->reset_resume && udev->persist_enabled) {
2079                         dev_dbg(&udev->dev, "retry with reset-resume\n");
2080                         udev->reset_resume = 1;
2081                         goto retry_reset_resume;
2082                 }
2083         }
2084
2085         if (status) {
2086                 dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
2087                                 status);
2088         } else if (udev->actconfig) {
2089                 le16_to_cpus(&devstatus);
2090                 if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
2091                         status = usb_control_msg(udev,
2092                                         usb_sndctrlpipe(udev, 0),
2093                                         USB_REQ_CLEAR_FEATURE,
2094                                                 USB_RECIP_DEVICE,
2095                                         USB_DEVICE_REMOTE_WAKEUP, 0,
2096                                         NULL, 0,
2097                                         USB_CTRL_SET_TIMEOUT);
2098                         if (status)
2099                                 dev_dbg(&udev->dev,
2100                                         "disable remote wakeup, status %d\n",
2101                                         status);
2102                 }
2103                 status = 0;
2104         }
2105         return status;
2106 }
2107
2108 /*
2109  * usb_port_resume - re-activate a suspended usb device's upstream port
2110  * @udev: device to re-activate, not a root hub
2111  * Context: must be able to sleep; device not locked; pm locks held
2112  *
2113  * This will re-activate the suspended device, increasing power usage
2114  * while letting drivers communicate again with its endpoints.
2115  * USB resume explicitly guarantees that the power session between
2116  * the host and the device is the same as it was when the device
2117  * suspended.
2118  *
2119  * If @udev->reset_resume is set then this routine won't check that the
2120  * port is still enabled.  Furthermore, finish_port_resume() above will
2121  * reset @udev.  The end result is that a broken power session can be
2122  * recovered and @udev will appear to persist across a loss of VBUS power.
2123  *
2124  * For example, if a host controller doesn't maintain VBUS suspend current
2125  * during a system sleep or is reset when the system wakes up, all the USB
2126  * power sessions below it will be broken.  This is especially troublesome
2127  * for mass-storage devices containing mounted filesystems, since the
2128  * device will appear to have disconnected and all the memory mappings
2129  * to it will be lost.  Using the USB_PERSIST facility, the device can be
2130  * made to appear as if it had not disconnected.
2131  *
2132  * This facility can be dangerous.  Although usb_reset_and_verify_device() makes
2133  * every effort to insure that the same device is present after the
2134  * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
2135  * quite possible for a device to remain unaltered but its media to be
2136  * changed.  If the user replaces a flash memory card while the system is
2137  * asleep, he will have only himself to blame when the filesystem on the
2138  * new card is corrupted and the system crashes.
2139  *
2140  * Returns 0 on success, else negative errno.
2141  */
2142 int usb_port_resume(struct usb_device *udev, pm_message_t msg)
2143 {
2144         struct usb_hub  *hub = hdev_to_hub(udev->parent);
2145         int             port1 = udev->portnum;
2146         int             status;
2147         u16             portchange, portstatus;
2148
2149         /* Skip the initial Clear-Suspend step for a remote wakeup */
2150         status = hub_port_status(hub, port1, &portstatus, &portchange);
2151         if (status == 0 && !(portstatus & USB_PORT_STAT_SUSPEND))
2152                 goto SuspendCleared;
2153
2154         // dev_dbg(hub->intfdev, "resume port %d\n", port1);
2155
2156         set_bit(port1, hub->busy_bits);
2157
2158         /* see 7.1.7.7; affects power usage, but not budgeting */
2159         status = clear_port_feature(hub->hdev,
2160                         port1, USB_PORT_FEAT_SUSPEND);
2161         if (status) {
2162                 dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
2163                                 port1, status);
2164         } else {
2165                 /* drive resume for at least 20 msec */
2166                 dev_dbg(&udev->dev, "usb %sresume\n",
2167                                 (msg.event & PM_EVENT_AUTO ? "auto-" : ""));
2168                 msleep(25);
2169
2170                 /* Virtual root hubs can trigger on GET_PORT_STATUS to
2171                  * stop resume signaling.  Then finish the resume
2172                  * sequence.
2173                  */
2174                 status = hub_port_status(hub, port1, &portstatus, &portchange);
2175
2176                 /* TRSMRCY = 10 msec */
2177                 msleep(10);
2178         }
2179
2180  SuspendCleared:
2181         if (status == 0) {
2182                 if (portchange & USB_PORT_STAT_C_SUSPEND)
2183                         clear_port_feature(hub->hdev, port1,
2184                                         USB_PORT_FEAT_C_SUSPEND);
2185         }
2186
2187         clear_bit(port1, hub->busy_bits);
2188
2189         status = check_port_resume_type(udev,
2190                         hub, port1, status, portchange, portstatus);
2191         if (status == 0)
2192                 status = finish_port_resume(udev);
2193         if (status < 0) {
2194                 dev_dbg(&udev->dev, "can't resume, status %d\n", status);
2195                 hub_port_logical_disconnect(hub, port1);
2196         }
2197         return status;
2198 }
2199
2200 /* caller has locked udev */
2201 static int remote_wakeup(struct usb_device *udev)
2202 {
2203         int     status = 0;
2204
2205         if (udev->state == USB_STATE_SUSPENDED) {
2206                 dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
2207                 usb_mark_last_busy(udev);
2208                 status = usb_external_resume_device(udev, PMSG_REMOTE_RESUME);
2209         }
2210         return status;
2211 }
2212
2213 #else   /* CONFIG_USB_SUSPEND */
2214
2215 /* When CONFIG_USB_SUSPEND isn't set, we never suspend or resume any ports. */
2216
2217 int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
2218 {
2219         return 0;
2220 }
2221
2222 /* However we may need to do a reset-resume */
2223
2224 int usb_port_resume(struct usb_device *udev, pm_message_t msg)
2225 {
2226         struct usb_hub  *hub = hdev_to_hub(udev->parent);
2227         int             port1 = udev->portnum;
2228         int             status;
2229         u16             portchange, portstatus;
2230
2231         status = hub_port_status(hub, port1, &portstatus, &portchange);
2232         status = check_port_resume_type(udev,
2233                         hub, port1, status, portchange, portstatus);
2234
2235         if (status) {
2236                 dev_dbg(&udev->dev, "can't resume, status %d\n", status);
2237                 hub_port_logical_disconnect(hub, port1);
2238         } else if (udev->reset_resume) {
2239                 dev_dbg(&udev->dev, "reset-resume\n");
2240                 status = usb_reset_and_verify_device(udev);
2241         }
2242         return status;
2243 }
2244
2245 static inline int remote_wakeup(struct usb_device *udev)
2246 {
2247         return 0;
2248 }
2249
2250 #endif
2251
2252 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
2253 {
2254         struct usb_hub          *hub = usb_get_intfdata (intf);
2255         struct usb_device       *hdev = hub->hdev;
2256         unsigned                port1;
2257
2258         /* fail if children aren't already suspended */
2259         for (port1 = 1; port1 <= hdev->maxchild; port1++) {
2260                 struct usb_device       *udev;
2261
2262                 udev = hdev->children [port1-1];
2263                 if (udev && udev->can_submit) {
2264                         if (!(msg.event & PM_EVENT_AUTO))
2265                                 dev_dbg(&intf->dev, "port %d nyet suspended\n",
2266                                                 port1);
2267                         return -EBUSY;
2268                 }
2269         }
2270
2271         dev_dbg(&intf->dev, "%s\n", __func__);
2272
2273         /* stop khubd and related activity */
2274         hub_quiesce(hub, HUB_SUSPEND);
2275         return 0;
2276 }
2277
2278 static int hub_resume(struct usb_interface *intf)
2279 {
2280         struct usb_hub *hub = usb_get_intfdata(intf);
2281
2282         dev_dbg(&intf->dev, "%s\n", __func__);
2283         hub_activate(hub, HUB_RESUME);
2284         return 0;
2285 }
2286
2287 static int hub_reset_resume(struct usb_interface *intf)
2288 {
2289         struct usb_hub *hub = usb_get_intfdata(intf);
2290
2291         dev_dbg(&intf->dev, "%s\n", __func__);
2292         hub_activate(hub, HUB_RESET_RESUME);
2293         return 0;
2294 }
2295
2296 /**
2297  * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
2298  * @rhdev: struct usb_device for the root hub
2299  *
2300  * The USB host controller driver calls this function when its root hub
2301  * is resumed and Vbus power has been interrupted or the controller
2302  * has been reset.  The routine marks @rhdev as having lost power.
2303  * When the hub driver is resumed it will take notice and carry out
2304  * power-session recovery for all the "USB-PERSIST"-enabled child devices;
2305  * the others will be disconnected.
2306  */
2307 void usb_root_hub_lost_power(struct usb_device *rhdev)
2308 {
2309         dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
2310         rhdev->reset_resume = 1;
2311 }
2312 EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
2313
2314 #else   /* CONFIG_PM */
2315
2316 static inline int remote_wakeup(struct usb_device *udev)
2317 {
2318         return 0;
2319 }
2320
2321 #define hub_suspend             NULL
2322 #define hub_resume              NULL
2323 #define hub_reset_resume        NULL
2324 #endif
2325
2326
2327 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
2328  *
2329  * Between connect detection and reset signaling there must be a delay
2330  * of 100ms at least for debounce and power-settling.  The corresponding
2331  * timer shall restart whenever the downstream port detects a disconnect.
2332  * 
2333  * Apparently there are some bluetooth and irda-dongles and a number of
2334  * low-speed devices for which this debounce period may last over a second.
2335  * Not covered by the spec - but easy to deal with.
2336  *
2337  * This implementation uses a 1500ms total debounce timeout; if the
2338  * connection isn't stable by then it returns -ETIMEDOUT.  It checks
2339  * every 25ms for transient disconnects.  When the port status has been
2340  * unchanged for 100ms it returns the port status.
2341  */
2342 static int hub_port_debounce(struct usb_hub *hub, int port1)
2343 {
2344         int ret;
2345         int total_time, stable_time = 0;
2346         u16 portchange, portstatus;
2347         unsigned connection = 0xffff;
2348
2349         for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
2350                 ret = hub_port_status(hub, port1, &portstatus, &portchange);
2351                 if (ret < 0)
2352                         return ret;
2353
2354                 if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
2355                      (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
2356                         stable_time += HUB_DEBOUNCE_STEP;
2357                         if (stable_time >= HUB_DEBOUNCE_STABLE)
2358                                 break;
2359                 } else {
2360                         stable_time = 0;
2361                         connection = portstatus & USB_PORT_STAT_CONNECTION;
2362                 }
2363
2364                 if (portchange & USB_PORT_STAT_C_CONNECTION) {
2365                         clear_port_feature(hub->hdev, port1,
2366                                         USB_PORT_FEAT_C_CONNECTION);
2367                 }
2368
2369                 if (total_time >= HUB_DEBOUNCE_TIMEOUT)
2370                         break;
2371                 msleep(HUB_DEBOUNCE_STEP);
2372         }
2373
2374         dev_dbg (hub->intfdev,
2375                 "debounce: port %d: total %dms stable %dms status 0x%x\n",
2376                 port1, total_time, stable_time, portstatus);
2377
2378         if (stable_time < HUB_DEBOUNCE_STABLE)
2379                 return -ETIMEDOUT;
2380         return portstatus;
2381 }
2382
2383 void usb_ep0_reinit(struct usb_device *udev)
2384 {
2385         usb_disable_endpoint(udev, 0 + USB_DIR_IN);
2386         usb_disable_endpoint(udev, 0 + USB_DIR_OUT);
2387         usb_enable_endpoint(udev, &udev->ep0, true);
2388 }
2389 EXPORT_SYMBOL_GPL(usb_ep0_reinit);
2390
2391 #define usb_sndaddr0pipe()      (PIPE_CONTROL << 30)
2392 #define usb_rcvaddr0pipe()      ((PIPE_CONTROL << 30) | USB_DIR_IN)
2393
2394 static int hub_set_address(struct usb_device *udev, int devnum)
2395 {
2396         int retval;
2397
2398         if (devnum <= 1)
2399                 return -EINVAL;
2400         if (udev->state == USB_STATE_ADDRESS)
2401                 return 0;
2402         if (udev->state != USB_STATE_DEFAULT)
2403                 return -EINVAL;
2404         retval = usb_control_msg(udev, usb_sndaddr0pipe(),
2405                 USB_REQ_SET_ADDRESS, 0, devnum, 0,
2406                 NULL, 0, USB_CTRL_SET_TIMEOUT);
2407         if (retval == 0) {
2408                 /* Device now using proper address. */
2409                 update_address(udev, devnum);
2410                 usb_set_device_state(udev, USB_STATE_ADDRESS);
2411                 usb_ep0_reinit(udev);
2412         }
2413         return retval;
2414 }
2415
2416 /* Reset device, (re)assign address, get device descriptor.
2417  * Device connection must be stable, no more debouncing needed.
2418  * Returns device in USB_STATE_ADDRESS, except on error.
2419  *
2420  * If this is called for an already-existing device (as part of
2421  * usb_reset_and_verify_device), the caller must own the device lock.  For a
2422  * newly detected device that is not accessible through any global
2423  * pointers, it's not necessary to lock the device.
2424  */
2425 static int
2426 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
2427                 int retry_counter)
2428 {
2429         static DEFINE_MUTEX(usb_address0_mutex);
2430
2431         struct usb_device       *hdev = hub->hdev;
2432         int                     i, j, retval;
2433         unsigned                delay = HUB_SHORT_RESET_TIME;
2434         enum usb_device_speed   oldspeed = udev->speed;
2435         char                    *speed, *type;
2436         int                     devnum = udev->devnum;
2437
2438         /* root hub ports have a slightly longer reset period
2439          * (from USB 2.0 spec, section 7.1.7.5)
2440          */
2441         if (!hdev->parent) {
2442                 delay = HUB_ROOT_RESET_TIME;
2443                 if (port1 == hdev->bus->otg_port)
2444                         hdev->bus->b_hnp_enable = 0;
2445         }
2446
2447         /* Some low speed devices have problems with the quick delay, so */
2448         /*  be a bit pessimistic with those devices. RHbug #23670 */
2449         if (oldspeed == USB_SPEED_LOW)
2450                 delay = HUB_LONG_RESET_TIME;
2451
2452         mutex_lock(&usb_address0_mutex);
2453
2454         /* Reset the device; full speed may morph to high speed */
2455         retval = hub_port_reset(hub, port1, udev, delay);
2456         if (retval < 0)         /* error or disconnect */
2457                 goto fail;
2458                                 /* success, speed is known */
2459         retval = -ENODEV;
2460
2461         if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
2462                 dev_dbg(&udev->dev, "device reset changed speed!\n");
2463                 goto fail;
2464         }
2465         oldspeed = udev->speed;
2466
2467         /* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
2468          * it's fixed size except for full speed devices.
2469          * For Wireless USB devices, ep0 max packet is always 512 (tho
2470          * reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
2471          */
2472         switch (udev->speed) {
2473         case USB_SPEED_VARIABLE:        /* fixed at 512 */
2474                 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(512);
2475                 break;
2476         case USB_SPEED_HIGH:            /* fixed at 64 */
2477                 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2478                 break;
2479         case USB_SPEED_FULL:            /* 8, 16, 32, or 64 */
2480                 /* to determine the ep0 maxpacket size, try to read
2481                  * the device descriptor to get bMaxPacketSize0 and
2482                  * then correct our initial guess.
2483                  */
2484                 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2485                 break;
2486         case USB_SPEED_LOW:             /* fixed at 8 */
2487                 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(8);
2488                 break;
2489         default:
2490                 goto fail;
2491         }
2492  
2493         type = "";
2494         switch (udev->speed) {
2495         case USB_SPEED_LOW:     speed = "low";  break;
2496         case USB_SPEED_FULL:    speed = "full"; break;
2497         case USB_SPEED_HIGH:    speed = "high"; break;
2498         case USB_SPEED_VARIABLE:
2499                                 speed = "variable";
2500                                 type = "Wireless ";
2501                                 break;
2502         default:                speed = "?";    break;
2503         }
2504         dev_info (&udev->dev,
2505                   "%s %s speed %sUSB device using %s and address %d\n",
2506                   (udev->config) ? "reset" : "new", speed, type,
2507                   udev->bus->controller->driver->name, devnum);
2508
2509         /* Set up TT records, if needed  */
2510         if (hdev->tt) {
2511                 udev->tt = hdev->tt;
2512                 udev->ttport = hdev->ttport;
2513         } else if (udev->speed != USB_SPEED_HIGH
2514                         && hdev->speed == USB_SPEED_HIGH) {
2515                 udev->tt = &hub->tt;
2516                 udev->ttport = port1;
2517         }
2518  
2519         /* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
2520          * Because device hardware and firmware is sometimes buggy in
2521          * this area, and this is how Linux has done it for ages.
2522          * Change it cautiously.
2523          *
2524          * NOTE:  If USE_NEW_SCHEME() is true we will start by issuing
2525          * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
2526          * so it may help with some non-standards-compliant devices.
2527          * Otherwise we start with SET_ADDRESS and then try to read the
2528          * first 8 bytes of the device descriptor to get the ep0 maxpacket
2529          * value.
2530          */
2531         for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
2532                 if (USE_NEW_SCHEME(retry_counter)) {
2533                         struct usb_device_descriptor *buf;
2534                         int r = 0;
2535
2536 #define GET_DESCRIPTOR_BUFSIZE  64
2537                         buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
2538                         if (!buf) {
2539                                 retval = -ENOMEM;
2540                                 continue;
2541                         }
2542
2543                         /* Retry on all errors; some devices are flakey.
2544                          * 255 is for WUSB devices, we actually need to use
2545                          * 512 (WUSB1.0[4.8.1]).
2546                          */
2547                         for (j = 0; j < 3; ++j) {
2548                                 buf->bMaxPacketSize0 = 0;
2549                                 r = usb_control_msg(udev, usb_rcvaddr0pipe(),
2550                                         USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
2551                                         USB_DT_DEVICE << 8, 0,
2552                                         buf, GET_DESCRIPTOR_BUFSIZE,
2553                                         initial_descriptor_timeout);
2554                                 switch (buf->bMaxPacketSize0) {
2555                                 case 8: case 16: case 32: case 64: case 255:
2556                                         if (buf->bDescriptorType ==
2557                                                         USB_DT_DEVICE) {
2558                                                 r = 0;
2559                                                 break;
2560                                         }
2561                                         /* FALL THROUGH */
2562                                 default:
2563                                         if (r == 0)
2564                                                 r = -EPROTO;
2565                                         break;
2566                                 }
2567                                 if (r == 0)
2568                                         break;
2569                         }
2570                         udev->descriptor.bMaxPacketSize0 =
2571                                         buf->bMaxPacketSize0;
2572                         kfree(buf);
2573
2574                         retval = hub_port_reset(hub, port1, udev, delay);
2575                         if (retval < 0)         /* error or disconnect */
2576                                 goto fail;
2577                         if (oldspeed != udev->speed) {
2578                                 dev_dbg(&udev->dev,
2579                                         "device reset changed speed!\n");
2580                                 retval = -ENODEV;
2581                                 goto fail;
2582                         }
2583                         if (r) {
2584                                 dev_err(&udev->dev,
2585                                         "device descriptor read/64, error %d\n",
2586                                         r);
2587                                 retval = -EMSGSIZE;
2588                                 continue;
2589                         }
2590 #undef GET_DESCRIPTOR_BUFSIZE
2591                 }
2592
2593                 /*
2594                  * If device is WUSB, we already assigned an
2595                  * unauthorized address in the Connect Ack sequence;
2596                  * authorization will assign the final address.
2597                  */
2598                 if (udev->wusb == 0) {
2599                         for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
2600                                 retval = hub_set_address(udev, devnum);
2601                                 if (retval >= 0)
2602                                         break;
2603                                 msleep(200);
2604                         }
2605                         if (retval < 0) {
2606                                 dev_err(&udev->dev,
2607                                         "device not accepting address %d, error %d\n",
2608                                         devnum, retval);
2609                                 goto fail;
2610                         }
2611
2612                         /* cope with hardware quirkiness:
2613                          *  - let SET_ADDRESS settle, some device hardware wants it
2614                          *  - read ep0 maxpacket even for high and low speed,
2615                          */
2616                         msleep(10);
2617                         if (USE_NEW_SCHEME(retry_counter))
2618                                 break;
2619                 }
2620
2621                 retval = usb_get_device_descriptor(udev, 8);
2622                 if (retval < 8) {
2623                         dev_err(&udev->dev,
2624                                         "device descriptor read/8, error %d\n",
2625                                         retval);
2626                         if (retval >= 0)
2627                                 retval = -EMSGSIZE;
2628                 } else {
2629                         retval = 0;
2630                         break;
2631                 }
2632         }
2633         if (retval)
2634                 goto fail;
2635
2636         i = udev->descriptor.bMaxPacketSize0 == 0xff?   /* wusb device? */
2637             512 : udev->descriptor.bMaxPacketSize0;
2638         if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) {
2639                 if (udev->speed != USB_SPEED_FULL ||
2640                                 !(i == 8 || i == 16 || i == 32 || i == 64)) {
2641                         dev_err(&udev->dev, "ep0 maxpacket = %d\n", i);
2642                         retval = -EMSGSIZE;
2643                         goto fail;
2644                 }
2645                 dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
2646                 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
2647                 usb_ep0_reinit(udev);
2648         }
2649   
2650         retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
2651         if (retval < (signed)sizeof(udev->descriptor)) {
2652                 dev_err(&udev->dev, "device descriptor read/all, error %d\n",
2653                         retval);
2654                 if (retval >= 0)
2655                         retval = -ENOMSG;
2656                 goto fail;
2657         }
2658
2659         retval = 0;
2660
2661 fail:
2662         if (retval) {
2663                 hub_port_disable(hub, port1, 0);
2664                 update_address(udev, devnum);   /* for disconnect processing */
2665         }
2666         mutex_unlock(&usb_address0_mutex);
2667         return retval;
2668 }
2669
2670 static void
2671 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
2672 {
2673         struct usb_qualifier_descriptor *qual;
2674         int                             status;
2675
2676         qual = kmalloc (sizeof *qual, GFP_KERNEL);
2677         if (qual == NULL)
2678                 return;
2679
2680         status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
2681                         qual, sizeof *qual);
2682         if (status == sizeof *qual) {
2683                 dev_info(&udev->dev, "not running at top speed; "
2684                         "connect to a high speed hub\n");
2685                 /* hub LEDs are probably harder to miss than syslog */
2686                 if (hub->has_indicators) {
2687                         hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
2688                         schedule_delayed_work (&hub->leds, 0);
2689                 }
2690         }
2691         kfree(qual);
2692 }
2693
2694 static unsigned
2695 hub_power_remaining (struct usb_hub *hub)
2696 {
2697         struct usb_device *hdev = hub->hdev;
2698         int remaining;
2699         int port1;
2700
2701         if (!hub->limited_power)
2702                 return 0;
2703
2704         remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
2705         for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
2706                 struct usb_device       *udev = hdev->children[port1 - 1];
2707                 int                     delta;
2708
2709                 if (!udev)
2710                         continue;
2711
2712                 /* Unconfigured devices may not use more than 100mA,
2713                  * or 8mA for OTG ports */
2714                 if (udev->actconfig)
2715                         delta = udev->actconfig->desc.bMaxPower * 2;
2716                 else if (port1 != udev->bus->otg_port || hdev->parent)
2717                         delta = 100;
2718                 else
2719                         delta = 8;
2720                 if (delta > hub->mA_per_port)
2721                         dev_warn(&udev->dev,
2722                                  "%dmA is over %umA budget for port %d!\n",
2723                                  delta, hub->mA_per_port, port1);
2724                 remaining -= delta;
2725         }
2726         if (remaining < 0) {
2727                 dev_warn(hub->intfdev, "%dmA over power budget!\n",
2728                         - remaining);
2729                 remaining = 0;
2730         }
2731         return remaining;
2732 }
2733
2734 /* Handle physical or logical connection change events.
2735  * This routine is called when:
2736  *      a port connection-change occurs;
2737  *      a port enable-change occurs (often caused by EMI);
2738  *      usb_reset_and_verify_device() encounters changed descriptors (as from
2739  *              a firmware download)
2740  * caller already locked the hub
2741  */
2742 static void hub_port_connect_change(struct usb_hub *hub, int port1,
2743                                         u16 portstatus, u16 portchange)
2744 {
2745         struct usb_device *hdev = hub->hdev;
2746         struct device *hub_dev = hub->intfdev;
2747         struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
2748         unsigned wHubCharacteristics =
2749                         le16_to_cpu(hub->descriptor->wHubCharacteristics);
2750         struct usb_device *udev;
2751         int status, i;
2752
2753         dev_dbg (hub_dev,
2754                 "port %d, status %04x, change %04x, %s\n",
2755                 port1, portstatus, portchange, portspeed (portstatus));
2756
2757         if (hub->has_indicators) {
2758                 set_port_led(hub, port1, HUB_LED_AUTO);
2759                 hub->indicator[port1-1] = INDICATOR_AUTO;
2760         }
2761
2762 #ifdef  CONFIG_USB_OTG
2763         /* during HNP, don't repeat the debounce */
2764         if (hdev->bus->is_b_host)
2765                 portchange &= ~(USB_PORT_STAT_C_CONNECTION |
2766                                 USB_PORT_STAT_C_ENABLE);
2767 #endif
2768
2769         /* Try to resuscitate an existing device */
2770         udev = hdev->children[port1-1];
2771         if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
2772                         udev->state != USB_STATE_NOTATTACHED) {
2773                 usb_lock_device(udev);
2774                 if (portstatus & USB_PORT_STAT_ENABLE) {
2775                         status = 0;             /* Nothing to do */
2776
2777 #ifdef CONFIG_USB_SUSPEND
2778                 } else if (udev->state == USB_STATE_SUSPENDED &&
2779                                 udev->persist_enabled) {
2780                         /* For a suspended device, treat this as a
2781                          * remote wakeup event.
2782                          */
2783                         if (udev->do_remote_wakeup)
2784                                 status = remote_wakeup(udev);
2785
2786                         /* Otherwise leave it be; devices can't tell the
2787                          * difference between suspended and disabled.
2788                          */
2789                         else
2790                                 status = 0;
2791 #endif
2792
2793                 } else {
2794                         status = -ENODEV;       /* Don't resuscitate */
2795                 }
2796                 usb_unlock_device(udev);
2797
2798                 if (status == 0) {
2799                         clear_bit(port1, hub->change_bits);
2800                         return;
2801                 }
2802         }
2803
2804         /* Disconnect any existing devices under this port */
2805         if (udev)
2806                 usb_disconnect(&hdev->children[port1-1]);
2807         clear_bit(port1, hub->change_bits);
2808
2809         if (portchange & (USB_PORT_STAT_C_CONNECTION |
2810                                 USB_PORT_STAT_C_ENABLE)) {
2811                 status = hub_port_debounce(hub, port1);
2812                 if (status < 0) {
2813                         if (printk_ratelimit())
2814                                 dev_err(hub_dev, "connect-debounce failed, "
2815                                                 "port %d disabled\n", port1);
2816                         portstatus &= ~USB_PORT_STAT_CONNECTION;
2817                 } else {
2818                         portstatus = status;
2819                 }
2820         }
2821
2822         /* Return now if debouncing failed or nothing is connected */
2823         if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
2824
2825                 /* maybe switch power back on (e.g. root hub was reset) */
2826                 if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2
2827                                 && !(portstatus & (1 << USB_PORT_FEAT_POWER)))
2828                         set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
2829
2830                 if (portstatus & USB_PORT_STAT_ENABLE)
2831                         goto done;
2832                 return;
2833         }
2834
2835         for (i = 0; i < SET_CONFIG_TRIES; i++) {
2836
2837                 /* reallocate for each attempt, since references
2838                  * to the previous one can escape in various ways
2839                  */
2840                 udev = usb_alloc_dev(hdev, hdev->bus, port1);
2841                 if (!udev) {
2842                         dev_err (hub_dev,
2843                                 "couldn't allocate port %d usb_device\n",
2844                                 port1);
2845                         goto done;
2846                 }
2847
2848                 usb_set_device_state(udev, USB_STATE_POWERED);
2849                 udev->speed = USB_SPEED_UNKNOWN;
2850                 udev->bus_mA = hub->mA_per_port;
2851                 udev->level = hdev->level + 1;
2852                 udev->wusb = hub_is_wusb(hub);
2853
2854                 /* set the address */
2855                 choose_address(udev);
2856                 if (udev->devnum <= 0) {
2857                         status = -ENOTCONN;     /* Don't retry */
2858                         goto loop;
2859                 }
2860
2861                 /* reset and get descriptor */
2862                 status = hub_port_init(hub, udev, port1, i);
2863                 if (status < 0)
2864                         goto loop;
2865
2866                 /* consecutive bus-powered hubs aren't reliable; they can
2867                  * violate the voltage drop budget.  if the new child has
2868                  * a "powered" LED, users should notice we didn't enable it
2869                  * (without reading syslog), even without per-port LEDs
2870                  * on the parent.
2871                  */
2872                 if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
2873                                 && udev->bus_mA <= 100) {
2874                         u16     devstat;
2875
2876                         status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
2877                                         &devstat);
2878                         if (status < 2) {
2879                                 dev_dbg(&udev->dev, "get status %d ?\n", status);
2880                                 goto loop_disable;
2881                         }
2882                         le16_to_cpus(&devstat);
2883                         if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
2884                                 dev_err(&udev->dev,
2885                                         "can't connect bus-powered hub "
2886                                         "to this port\n");
2887                                 if (hub->has_indicators) {
2888                                         hub->indicator[port1-1] =
2889                                                 INDICATOR_AMBER_BLINK;
2890                                         schedule_delayed_work (&hub->leds, 0);
2891                                 }
2892                                 status = -ENOTCONN;     /* Don't retry */
2893                                 goto loop_disable;
2894                         }
2895                 }
2896  
2897                 /* check for devices running slower than they could */
2898                 if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
2899                                 && udev->speed == USB_SPEED_FULL
2900                                 && highspeed_hubs != 0)
2901                         check_highspeed (hub, udev, port1);
2902
2903                 /* Store the parent's children[] pointer.  At this point
2904                  * udev becomes globally accessible, although presumably
2905                  * no one will look at it until hdev is unlocked.
2906                  */
2907                 status = 0;
2908
2909                 /* We mustn't add new devices if the parent hub has
2910                  * been disconnected; we would race with the
2911                  * recursively_mark_NOTATTACHED() routine.
2912                  */
2913                 spin_lock_irq(&device_state_lock);
2914                 if (hdev->state == USB_STATE_NOTATTACHED)
2915                         status = -ENOTCONN;
2916                 else
2917                         hdev->children[port1-1] = udev;
2918                 spin_unlock_irq(&device_state_lock);
2919
2920                 /* Run it through the hoops (find a driver, etc) */
2921                 if (!status) {
2922                         status = usb_new_device(udev);
2923                         if (status) {
2924                                 spin_lock_irq(&device_state_lock);
2925                                 hdev->children[port1-1] = NULL;
2926                                 spin_unlock_irq(&device_state_lock);
2927                         }
2928                 }
2929
2930                 if (status)
2931                         goto loop_disable;
2932
2933                 status = hub_power_remaining(hub);
2934                 if (status)
2935                         dev_dbg(hub_dev, "%dmA power budget left\n", status);
2936
2937                 return;
2938
2939 loop_disable:
2940                 hub_port_disable(hub, port1, 1);
2941 loop:
2942                 usb_ep0_reinit(udev);
2943                 release_address(udev);
2944                 usb_put_dev(udev);
2945                 if ((status == -ENOTCONN) || (status == -ENOTSUPP))
2946                         break;
2947         }
2948         if (hub->hdev->parent ||
2949                         !hcd->driver->port_handed_over ||
2950                         !(hcd->driver->port_handed_over)(hcd, port1))
2951                 dev_err(hub_dev, "unable to enumerate USB device on port %d\n",
2952                                 port1);
2953  
2954 done:
2955         hub_port_disable(hub, port1, 1);
2956         if (hcd->driver->relinquish_port && !hub->hdev->parent)
2957                 hcd->driver->relinquish_port(hcd, port1);
2958 }
2959
2960 static void hub_events(void)
2961 {
2962         struct list_head *tmp;
2963         struct usb_device *hdev;
2964         struct usb_interface *intf;
2965         struct usb_hub *hub;
2966         struct device *hub_dev;
2967         u16 hubstatus;
2968         u16 hubchange;
2969         u16 portstatus;
2970         u16 portchange;
2971         int i, ret;
2972         int connect_change;
2973
2974         /*
2975          *  We restart the list every time to avoid a deadlock with
2976          * deleting hubs downstream from this one. This should be
2977          * safe since we delete the hub from the event list.
2978          * Not the most efficient, but avoids deadlocks.
2979          */
2980         while (1) {
2981
2982                 /* Grab the first entry at the beginning of the list */
2983                 spin_lock_irq(&hub_event_lock);
2984                 if (list_empty(&hub_event_list)) {
2985                         spin_unlock_irq(&hub_event_lock);
2986                         break;
2987                 }
2988
2989                 tmp = hub_event_list.next;
2990                 list_del_init(tmp);
2991
2992                 hub = list_entry(tmp, struct usb_hub, event_list);
2993                 kref_get(&hub->kref);
2994                 spin_unlock_irq(&hub_event_lock);
2995
2996                 hdev = hub->hdev;
2997                 hub_dev = hub->intfdev;
2998                 intf = to_usb_interface(hub_dev);
2999                 dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
3000                                 hdev->state, hub->descriptor
3001                                         ? hub->descriptor->bNbrPorts
3002                                         : 0,
3003                                 /* NOTE: expects max 15 ports... */
3004                                 (u16) hub->change_bits[0],
3005                                 (u16) hub->event_bits[0]);
3006
3007                 /* Lock the device, then check to see if we were
3008                  * disconnected while waiting for the lock to succeed. */
3009                 usb_lock_device(hdev);
3010                 if (unlikely(hub->disconnected))
3011                         goto loop;
3012
3013                 /* If the hub has died, clean up after it */
3014                 if (hdev->state == USB_STATE_NOTATTACHED) {
3015                         hub->error = -ENODEV;
3016                         hub_quiesce(hub, HUB_DISCONNECT);
3017                         goto loop;
3018                 }
3019
3020                 /* Autoresume */
3021                 ret = usb_autopm_get_interface(intf);
3022                 if (ret) {
3023                         dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
3024                         goto loop;
3025                 }
3026
3027                 /* If this is an inactive hub, do nothing */
3028                 if (hub->quiescing)
3029                         goto loop_autopm;
3030
3031                 if (hub->error) {
3032                         dev_dbg (hub_dev, "resetting for error %d\n",
3033                                 hub->error);
3034
3035                         ret = usb_reset_device(hdev);
3036                         if (ret) {
3037                                 dev_dbg (hub_dev,
3038                                         "error resetting hub: %d\n", ret);
3039                                 goto loop_autopm;
3040                         }
3041
3042                         hub->nerrors = 0;
3043                         hub->error = 0;
3044                 }
3045
3046                 /* deal with port status changes */
3047                 for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
3048                         if (test_bit(i, hub->busy_bits))
3049                                 continue;
3050                         connect_change = test_bit(i, hub->change_bits);
3051                         if (!test_and_clear_bit(i, hub->event_bits) &&
3052                                         !connect_change)
3053                                 continue;
3054
3055                         ret = hub_port_status(hub, i,
3056                                         &portstatus, &portchange);
3057                         if (ret < 0)
3058                                 continue;
3059
3060                         if (portchange & USB_PORT_STAT_C_CONNECTION) {
3061                                 clear_port_feature(hdev, i,
3062                                         USB_PORT_FEAT_C_CONNECTION);
3063                                 connect_change = 1;
3064                         }
3065
3066                         if (portchange & USB_PORT_STAT_C_ENABLE) {
3067                                 if (!connect_change)
3068                                         dev_dbg (hub_dev,
3069                                                 "port %d enable change, "
3070                                                 "status %08x\n",
3071                                                 i, portstatus);
3072                                 clear_port_feature(hdev, i,
3073                                         USB_PORT_FEAT_C_ENABLE);
3074
3075                                 /*
3076                                  * EM interference sometimes causes badly
3077                                  * shielded USB devices to be shutdown by
3078                                  * the hub, this hack enables them again.
3079                                  * Works at least with mouse driver. 
3080                                  */
3081                                 if (!(portstatus & USB_PORT_STAT_ENABLE)
3082                                     && !connect_change
3083                                     && hdev->children[i-1]) {
3084                                         dev_err (hub_dev,
3085                                             "port %i "
3086                                             "disabled by hub (EMI?), "
3087                                             "re-enabling...\n",
3088                                                 i);
3089                                         connect_change = 1;
3090                                 }
3091                         }
3092
3093                         if (portchange & USB_PORT_STAT_C_SUSPEND) {
3094                                 struct usb_device *udev;
3095
3096                                 clear_port_feature(hdev, i,
3097                                         USB_PORT_FEAT_C_SUSPEND);
3098                                 udev = hdev->children[i-1];
3099                                 if (udev) {
3100                                         usb_lock_device(udev);
3101                                         ret = remote_wakeup(hdev->
3102                                                         children[i-1]);
3103                                         usb_unlock_device(udev);
3104                                         if (ret < 0)
3105                                                 connect_change = 1;
3106                                 } else {
3107                                         ret = -ENODEV;
3108                                         hub_port_disable(hub, i, 1);
3109                                 }
3110                                 dev_dbg (hub_dev,
3111                                         "resume on port %d, status %d\n",
3112                                         i, ret);
3113                         }
3114                         
3115                         if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
3116                                 dev_err (hub_dev,
3117                                         "over-current change on port %d\n",
3118                                         i);
3119                                 clear_port_feature(hdev, i,
3120                                         USB_PORT_FEAT_C_OVER_CURRENT);
3121                                 hub_power_on(hub, true);
3122                         }
3123
3124                         if (portchange & USB_PORT_STAT_C_RESET) {
3125                                 dev_dbg (hub_dev,
3126                                         "reset change on port %d\n",
3127                                         i);
3128                                 clear_port_feature(hdev, i,
3129                                         USB_PORT_FEAT_C_RESET);
3130                         }
3131
3132                         if (connect_change)
3133                                 hub_port_connect_change(hub, i,
3134                                                 portstatus, portchange);
3135                 } /* end for i */
3136
3137                 /* deal with hub status changes */
3138                 if (test_and_clear_bit(0, hub->event_bits) == 0)
3139                         ;       /* do nothing */
3140                 else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
3141                         dev_err (hub_dev, "get_hub_status failed\n");
3142                 else {
3143                         if (hubchange & HUB_CHANGE_LOCAL_POWER) {
3144                                 dev_dbg (hub_dev, "power change\n");
3145                                 clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
3146                                 if (hubstatus & HUB_STATUS_LOCAL_POWER)
3147                                         /* FIXME: Is this always true? */
3148                                         hub->limited_power = 1;
3149                                 else
3150                                         hub->limited_power = 0;
3151                         }
3152                         if (hubchange & HUB_CHANGE_OVERCURRENT) {
3153                                 dev_dbg (hub_dev, "overcurrent change\n");
3154                                 msleep(500);    /* Cool down */
3155                                 clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
3156                                 hub_power_on(hub, true);
3157                         }
3158                 }
3159
3160 loop_autopm:
3161                 /* Allow autosuspend if we're not going to run again */
3162                 if (list_empty(&hub->event_list))
3163                         usb_autopm_enable(intf);
3164 loop:
3165                 usb_unlock_device(hdev);
3166                 kref_put(&hub->kref, hub_release);
3167
3168         } /* end while (1) */
3169 }
3170
3171 static int hub_thread(void *__unused)
3172 {
3173         /* khubd needs to be freezable to avoid intefering with USB-PERSIST
3174          * port handover.  Otherwise it might see that a full-speed device
3175          * was gone before the EHCI controller had handed its port over to
3176          * the companion full-speed controller.
3177          */
3178         set_freezable();
3179
3180         do {
3181                 hub_events();
3182                 wait_event_freezable(khubd_wait,
3183                                 !list_empty(&hub_event_list) ||
3184                                 kthread_should_stop());
3185         } while (!kthread_should_stop() || !list_empty(&hub_event_list));
3186
3187         pr_debug("%s: khubd exiting\n", usbcore_name);
3188         return 0;
3189 }
3190
3191 static struct usb_device_id hub_id_table [] = {
3192     { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
3193       .bDeviceClass = USB_CLASS_HUB},
3194     { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
3195       .bInterfaceClass = USB_CLASS_HUB},
3196     { }                                         /* Terminating entry */
3197 };
3198
3199 MODULE_DEVICE_TABLE (usb, hub_id_table);
3200
3201 static struct usb_driver hub_driver = {
3202         .name =         "hub",
3203         .probe =        hub_probe,
3204         .disconnect =   hub_disconnect,
3205         .suspend =      hub_suspend,
3206         .resume =       hub_resume,
3207         .reset_resume = hub_reset_resume,
3208         .pre_reset =    hub_pre_reset,
3209         .post_reset =   hub_post_reset,
3210         .ioctl =        hub_ioctl,
3211         .id_table =     hub_id_table,
3212         .supports_autosuspend = 1,
3213 };
3214
3215 int usb_hub_init(void)
3216 {
3217         if (usb_register(&hub_driver) < 0) {
3218                 printk(KERN_ERR "%s: can't register hub driver\n",
3219                         usbcore_name);
3220                 return -1;
3221         }
3222
3223         khubd_task = kthread_run(hub_thread, NULL, "khubd");
3224         if (!IS_ERR(khubd_task))
3225                 return 0;
3226
3227         /* Fall through if kernel_thread failed */
3228         usb_deregister(&hub_driver);
3229         printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
3230
3231         return -1;
3232 }
3233
3234 void usb_hub_cleanup(void)
3235 {
3236         kthread_stop(khubd_task);
3237
3238         /*
3239          * Hub resources are freed for us by usb_deregister. It calls
3240          * usb_driver_purge on every device which in turn calls that
3241          * devices disconnect function if it is using this driver.
3242          * The hub_disconnect function takes care of releasing the
3243          * individual hub resources. -greg
3244          */
3245         usb_deregister(&hub_driver);
3246 } /* usb_hub_cleanup() */
3247
3248 static int descriptors_changed(struct usb_device *udev,
3249                 struct usb_device_descriptor *old_device_descriptor)
3250 {
3251         int             changed = 0;
3252         unsigned        index;
3253         unsigned        serial_len = 0;
3254         unsigned        len;
3255         unsigned        old_length;
3256         int             length;
3257         char            *buf;
3258
3259         if (memcmp(&udev->descriptor, old_device_descriptor,
3260                         sizeof(*old_device_descriptor)) != 0)
3261                 return 1;
3262
3263         /* Since the idVendor, idProduct, and bcdDevice values in the
3264          * device descriptor haven't changed, we will assume the
3265          * Manufacturer and Product strings haven't changed either.
3266          * But the SerialNumber string could be different (e.g., a
3267          * different flash card of the same brand).
3268          */
3269         if (udev->serial)
3270                 serial_len = strlen(udev->serial) + 1;
3271
3272         len = serial_len;
3273         for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
3274                 old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
3275                 len = max(len, old_length);
3276         }
3277
3278         buf = kmalloc(len, GFP_NOIO);
3279         if (buf == NULL) {
3280                 dev_err(&udev->dev, "no mem to re-read configs after reset\n");
3281                 /* assume the worst */
3282                 return 1;
3283         }
3284         for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
3285                 old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
3286                 length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
3287                                 old_length);
3288                 if (length != old_length) {
3289                         dev_dbg(&udev->dev, "config index %d, error %d\n",
3290                                         index, length);
3291                         changed = 1;
3292                         break;
3293                 }
3294                 if (memcmp (buf, udev->rawdescriptors[index], old_length)
3295                                 != 0) {
3296                         dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
3297                                 index,
3298                                 ((struct usb_config_descriptor *) buf)->
3299                                         bConfigurationValue);
3300                         changed = 1;
3301                         break;
3302                 }
3303         }
3304
3305         if (!changed && serial_len) {
3306                 length = usb_string(udev, udev->descriptor.iSerialNumber,
3307                                 buf, serial_len);
3308                 if (length + 1 != serial_len) {
3309                         dev_dbg(&udev->dev, "serial string error %d\n",
3310                                         length);
3311                         changed = 1;
3312                 } else if (memcmp(buf, udev->serial, length) != 0) {
3313                         dev_dbg(&udev->dev, "serial string changed\n");
3314                         changed = 1;
3315                 }
3316         }
3317
3318         kfree(buf);
3319         return changed;
3320 }
3321
3322 /**
3323  * usb_reset_and_verify_device - perform a USB port reset to reinitialize a device
3324  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
3325  *
3326  * WARNING - don't use this routine to reset a composite device
3327  * (one with multiple interfaces owned by separate drivers)!
3328  * Use usb_reset_device() instead.
3329  *
3330  * Do a port reset, reassign the device's address, and establish its
3331  * former operating configuration.  If the reset fails, or the device's
3332  * descriptors change from their values before the reset, or the original
3333  * configuration and altsettings cannot be restored, a flag will be set
3334  * telling khubd to pretend the device has been disconnected and then
3335  * re-connected.  All drivers will be unbound, and the device will be
3336  * re-enumerated and probed all over again.
3337  *
3338  * Returns 0 if the reset succeeded, -ENODEV if the device has been
3339  * flagged for logical disconnection, or some other negative error code
3340  * if the reset wasn't even attempted.
3341  *
3342  * The caller must own the device lock.  For example, it's safe to use
3343  * this from a driver probe() routine after downloading new firmware.
3344  * For calls that might not occur during probe(), drivers should lock
3345  * the device using usb_lock_device_for_reset().
3346  *
3347  * Locking exception: This routine may also be called from within an
3348  * autoresume handler.  Such usage won't conflict with other tasks
3349  * holding the device lock because these tasks should always call
3350  * usb_autopm_resume_device(), thereby preventing any unwanted autoresume.
3351  */
3352 static int usb_reset_and_verify_device(struct usb_device *udev)
3353 {
3354         struct usb_device               *parent_hdev = udev->parent;
3355         struct usb_hub                  *parent_hub;
3356         struct usb_device_descriptor    descriptor = udev->descriptor;
3357         int                             i, ret = 0;
3358         int                             port1 = udev->portnum;
3359
3360         if (udev->state == USB_STATE_NOTATTACHED ||
3361                         udev->state == USB_STATE_SUSPENDED) {
3362                 dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
3363                                 udev->state);
3364                 return -EINVAL;
3365         }
3366
3367         if (!parent_hdev) {
3368                 /* this requires hcd-specific logic; see OHCI hc_restart() */
3369                 dev_dbg(&udev->dev, "%s for root hub!\n", __func__);
3370                 return -EISDIR;
3371         }
3372         parent_hub = hdev_to_hub(parent_hdev);
3373
3374         set_bit(port1, parent_hub->busy_bits);
3375         for (i = 0; i < SET_CONFIG_TRIES; ++i) {
3376
3377                 /* ep0 maxpacket size may change; let the HCD know about it.
3378                  * Other endpoints will be handled by re-enumeration. */
3379                 usb_ep0_reinit(udev);
3380                 ret = hub_port_init(parent_hub, udev, port1, i);
3381                 if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
3382                         break;
3383         }
3384         clear_bit(port1, parent_hub->busy_bits);
3385
3386         if (ret < 0)
3387                 goto re_enumerate;
3388  
3389         /* Device might have changed firmware (DFU or similar) */
3390         if (descriptors_changed(udev, &descriptor)) {
3391                 dev_info(&udev->dev, "device firmware changed\n");
3392                 udev->descriptor = descriptor;  /* for disconnect() calls */
3393                 goto re_enumerate;
3394         }
3395   
3396         if (!udev->actconfig)
3397                 goto done;
3398
3399         ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3400                         USB_REQ_SET_CONFIGURATION, 0,
3401                         udev->actconfig->desc.bConfigurationValue, 0,
3402                         NULL, 0, USB_CTRL_SET_TIMEOUT);
3403         if (ret < 0) {
3404                 dev_err(&udev->dev,
3405                         "can't restore configuration #%d (error=%d)\n",
3406                         udev->actconfig->desc.bConfigurationValue, ret);
3407                 goto re_enumerate;
3408         }
3409         usb_set_device_state(udev, USB_STATE_CONFIGURED);
3410
3411         for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
3412                 struct usb_interface *intf = udev->actconfig->interface[i];
3413                 struct usb_interface_descriptor *desc;
3414
3415                 /* set_interface resets host side toggle even
3416                  * for altsetting zero.  the interface may have no driver.
3417                  */
3418                 desc = &intf->cur_altsetting->desc;
3419                 ret = usb_set_interface(udev, desc->bInterfaceNumber,
3420                         desc->bAlternateSetting);
3421                 if (ret < 0) {
3422                         dev_err(&udev->dev, "failed to restore interface %d "
3423                                 "altsetting %d (error=%d)\n",
3424                                 desc->bInterfaceNumber,
3425                                 desc->bAlternateSetting,
3426                                 ret);
3427                         goto re_enumerate;
3428                 }
3429         }
3430
3431 done:
3432         return 0;
3433  
3434 re_enumerate:
3435         hub_port_logical_disconnect(parent_hub, port1);
3436         return -ENODEV;
3437 }
3438
3439 /**
3440  * usb_reset_device - warn interface drivers and perform a USB port reset
3441  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
3442  *
3443  * Warns all drivers bound to registered interfaces (using their pre_reset
3444  * method), performs the port reset, and then lets the drivers know that
3445  * the reset is over (using their post_reset method).
3446  *
3447  * Return value is the same as for usb_reset_and_verify_device().
3448  *
3449  * The caller must own the device lock.  For example, it's safe to use
3450  * this from a driver probe() routine after downloading new firmware.
3451  * For calls that might not occur during probe(), drivers should lock
3452  * the device using usb_lock_device_for_reset().
3453  *
3454  * If an interface is currently being probed or disconnected, we assume
3455  * its driver knows how to handle resets.  For all other interfaces,
3456  * if the driver doesn't have pre_reset and post_reset methods then
3457  * we attempt to unbind it and rebind afterward.
3458  */
3459 int usb_reset_device(struct usb_device *udev)
3460 {
3461         int ret;
3462         int i;
3463         struct usb_host_config *config = udev->actconfig;
3464
3465         if (udev->state == USB_STATE_NOTATTACHED ||
3466                         udev->state == USB_STATE_SUSPENDED) {
3467                 dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
3468                                 udev->state);
3469                 return -EINVAL;
3470         }
3471
3472         /* Prevent autosuspend during the reset */
3473         usb_autoresume_device(udev);
3474
3475         if (config) {
3476                 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
3477                         struct usb_interface *cintf = config->interface[i];
3478                         struct usb_driver *drv;
3479                         int unbind = 0;
3480
3481                         if (cintf->dev.driver) {
3482                                 drv = to_usb_driver(cintf->dev.driver);
3483                                 if (drv->pre_reset && drv->post_reset)
3484                                         unbind = (drv->pre_reset)(cintf);
3485                                 else if (cintf->condition ==
3486                                                 USB_INTERFACE_BOUND)
3487                                         unbind = 1;
3488                                 if (unbind)
3489                                         usb_forced_unbind_intf(cintf);
3490                         }
3491                 }
3492         }
3493
3494         ret = usb_reset_and_verify_device(udev);
3495
3496         if (config) {
3497                 for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
3498                         struct usb_interface *cintf = config->interface[i];
3499                         struct usb_driver *drv;
3500                         int rebind = cintf->needs_binding;
3501
3502                         if (!rebind && cintf->dev.driver) {
3503                                 drv = to_usb_driver(cintf->dev.driver);
3504                                 if (drv->post_reset)
3505                                         rebind = (drv->post_reset)(cintf);
3506                                 else if (cintf->condition ==
3507                                                 USB_INTERFACE_BOUND)
3508                                         rebind = 1;
3509                         }
3510                         if (ret == 0 && rebind)
3511                                 usb_rebind_intf(cintf);
3512                 }
3513         }
3514
3515         usb_autosuspend_device(udev);
3516         return ret;
3517 }
3518 EXPORT_SYMBOL_GPL(usb_reset_device);
3519
3520
3521 /**
3522  * usb_queue_reset_device - Reset a USB device from an atomic context
3523  * @iface: USB interface belonging to the device to reset
3524  *
3525  * This function can be used to reset a USB device from an atomic
3526  * context, where usb_reset_device() won't work (as it blocks).
3527  *
3528  * Doing a reset via this method is functionally equivalent to calling
3529  * usb_reset_device(), except for the fact that it is delayed to a
3530  * workqueue. This means that any drivers bound to other interfaces
3531  * might be unbound, as well as users from usbfs in user space.
3532  *
3533  * Corner cases:
3534  *
3535  * - Scheduling two resets at the same time from two different drivers
3536  *   attached to two different interfaces of the same device is
3537  *   possible; depending on how the driver attached to each interface
3538  *   handles ->pre_reset(), the second reset might happen or not.
3539  *
3540  * - If a driver is unbound and it had a pending reset, the reset will
3541  *   be cancelled.
3542  *
3543  * - This function can be called during .probe() or .disconnect()
3544  *   times. On return from .disconnect(), any pending resets will be
3545  *   cancelled.
3546  *
3547  * There is no no need to lock/unlock the @reset_ws as schedule_work()
3548  * does its own.
3549  *
3550  * NOTE: We don't do any reference count tracking because it is not
3551  *     needed. The lifecycle of the work_struct is tied to the
3552  *     usb_interface. Before destroying the interface we cancel the
3553  *     work_struct, so the fact that work_struct is queued and or
3554  *     running means the interface (and thus, the device) exist and
3555  *     are referenced.
3556  */
3557 void usb_queue_reset_device(struct usb_interface *iface)
3558 {
3559         schedule_work(&iface->reset_ws);
3560 }
3561 EXPORT_SYMBOL_GPL(usb_queue_reset_device);