USB: Implement support for EHCI with big endian MMIO
[linux-2.6] / drivers / usb / host / ehci-hub.c
1 /*
2  * Copyright (C) 2001-2004 by David Brownell
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License as published by the
6  * Free Software Foundation; either version 2 of the License, or (at your
7  * option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software Foundation,
16  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17  */
18
19 /* this file is part of ehci-hcd.c */
20
21 /*-------------------------------------------------------------------------*/
22
23 /*
24  * EHCI Root Hub ... the nonsharable stuff
25  *
26  * Registers don't need cpu_to_le32, that happens transparently
27  */
28
29 /*-------------------------------------------------------------------------*/
30
31 #ifdef  CONFIG_PM
32
33 static int ehci_bus_suspend (struct usb_hcd *hcd)
34 {
35         struct ehci_hcd         *ehci = hcd_to_ehci (hcd);
36         int                     port;
37         int                     mask;
38
39         if (time_before (jiffies, ehci->next_statechange))
40                 msleep(5);
41
42         port = HCS_N_PORTS (ehci->hcs_params);
43         spin_lock_irq (&ehci->lock);
44
45         /* stop schedules, clean any completed work */
46         if (HC_IS_RUNNING(hcd->state)) {
47                 ehci_quiesce (ehci);
48                 hcd->state = HC_STATE_QUIESCING;
49         }
50         ehci->command = ehci_readl(ehci, &ehci->regs->command);
51         if (ehci->reclaim)
52                 ehci->reclaim_ready = 1;
53         ehci_work(ehci);
54
55         /* Unlike other USB host controller types, EHCI doesn't have
56          * any notion of "global" or bus-wide suspend.  The driver has
57          * to manually suspend all the active unsuspended ports, and
58          * then manually resume them in the bus_resume() routine.
59          */
60         ehci->bus_suspended = 0;
61         while (port--) {
62                 u32 __iomem     *reg = &ehci->regs->port_status [port];
63                 u32             t1 = ehci_readl(ehci, reg) & ~PORT_RWC_BITS;
64                 u32             t2 = t1;
65
66                 /* keep track of which ports we suspend */
67                 if ((t1 & PORT_PE) && !(t1 & PORT_OWNER) &&
68                                 !(t1 & PORT_SUSPEND)) {
69                         t2 |= PORT_SUSPEND;
70                         set_bit(port, &ehci->bus_suspended);
71                 }
72
73                 /* enable remote wakeup on all ports */
74                 if (device_may_wakeup(&hcd->self.root_hub->dev))
75                         t2 |= PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E;
76                 else
77                         t2 &= ~(PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E);
78
79                 if (t1 != t2) {
80                         ehci_vdbg (ehci, "port %d, %08x -> %08x\n",
81                                 port + 1, t1, t2);
82                         ehci_writel(ehci, t2, reg);
83                 }
84         }
85
86         /* turn off now-idle HC */
87         del_timer_sync (&ehci->watchdog);
88         ehci_halt (ehci);
89         hcd->state = HC_STATE_SUSPENDED;
90
91         /* allow remote wakeup */
92         mask = INTR_MASK;
93         if (!device_may_wakeup(&hcd->self.root_hub->dev))
94                 mask &= ~STS_PCD;
95         ehci_writel(ehci, mask, &ehci->regs->intr_enable);
96         ehci_readl(ehci, &ehci->regs->intr_enable);
97
98         ehci->next_statechange = jiffies + msecs_to_jiffies(10);
99         spin_unlock_irq (&ehci->lock);
100         return 0;
101 }
102
103
104 /* caller has locked the root hub, and should reset/reinit on error */
105 static int ehci_bus_resume (struct usb_hcd *hcd)
106 {
107         struct ehci_hcd         *ehci = hcd_to_ehci (hcd);
108         u32                     temp;
109         int                     i;
110
111         if (time_before (jiffies, ehci->next_statechange))
112                 msleep(5);
113         spin_lock_irq (&ehci->lock);
114
115         /* Ideally and we've got a real resume here, and no port's power
116          * was lost.  (For PCI, that means Vaux was maintained.)  But we
117          * could instead be restoring a swsusp snapshot -- so that BIOS was
118          * the last user of the controller, not reset/pm hardware keeping
119          * state we gave to it.
120          */
121         temp = ehci_readl(ehci, &ehci->regs->intr_enable);
122         ehci_dbg(ehci, "resume root hub%s\n", temp ? "" : " after power loss");
123
124         /* at least some APM implementations will try to deliver
125          * IRQs right away, so delay them until we're ready.
126          */
127         ehci_writel(ehci, 0, &ehci->regs->intr_enable);
128
129         /* re-init operational registers */
130         ehci_writel(ehci, 0, &ehci->regs->segment);
131         ehci_writel(ehci, ehci->periodic_dma, &ehci->regs->frame_list);
132         ehci_writel(ehci, (u32) ehci->async->qh_dma, &ehci->regs->async_next);
133
134         /* restore CMD_RUN, framelist size, and irq threshold */
135         ehci_writel(ehci, ehci->command, &ehci->regs->command);
136
137         /* manually resume the ports we suspended during bus_suspend() */
138         i = HCS_N_PORTS (ehci->hcs_params);
139         while (i--) {
140                 temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
141                 temp &= ~(PORT_RWC_BITS
142                         | PORT_WKOC_E | PORT_WKDISC_E | PORT_WKCONN_E);
143                 if (test_bit(i, &ehci->bus_suspended) &&
144                                 (temp & PORT_SUSPEND)) {
145                         ehci->reset_done [i] = jiffies + msecs_to_jiffies (20);
146                         temp |= PORT_RESUME;
147                 }
148                 ehci_writel(ehci, temp, &ehci->regs->port_status [i]);
149         }
150         i = HCS_N_PORTS (ehci->hcs_params);
151         mdelay (20);
152         while (i--) {
153                 temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
154                 if (test_bit(i, &ehci->bus_suspended) &&
155                                 (temp & PORT_SUSPEND)) {
156                         temp &= ~(PORT_RWC_BITS | PORT_RESUME);
157                         ehci_writel(ehci, temp, &ehci->regs->port_status [i]);
158                         ehci_vdbg (ehci, "resumed port %d\n", i + 1);
159                 }
160         }
161         (void) ehci_readl(ehci, &ehci->regs->command);
162
163         /* maybe re-activate the schedule(s) */
164         temp = 0;
165         if (ehci->async->qh_next.qh)
166                 temp |= CMD_ASE;
167         if (ehci->periodic_sched)
168                 temp |= CMD_PSE;
169         if (temp) {
170                 ehci->command |= temp;
171                 ehci_writel(ehci, ehci->command, &ehci->regs->command);
172         }
173
174         ehci->next_statechange = jiffies + msecs_to_jiffies(5);
175         hcd->state = HC_STATE_RUNNING;
176
177         /* Now we can safely re-enable irqs */
178         ehci_writel(ehci, INTR_MASK, &ehci->regs->intr_enable);
179
180         spin_unlock_irq (&ehci->lock);
181         return 0;
182 }
183
184 #else
185
186 #define ehci_bus_suspend        NULL
187 #define ehci_bus_resume         NULL
188
189 #endif  /* CONFIG_PM */
190
191 /*-------------------------------------------------------------------------*/
192
193 static int check_reset_complete (
194         struct ehci_hcd *ehci,
195         int             index,
196         int             port_status
197 ) {
198         if (!(port_status & PORT_CONNECT)) {
199                 ehci->reset_done [index] = 0;
200                 return port_status;
201         }
202
203         /* if reset finished and it's still not enabled -- handoff */
204         if (!(port_status & PORT_PE)) {
205
206                 /* with integrated TT, there's nobody to hand it to! */
207                 if (ehci_is_TDI(ehci)) {
208                         ehci_dbg (ehci,
209                                 "Failed to enable port %d on root hub TT\n",
210                                 index+1);
211                         return port_status;
212                 }
213
214                 ehci_dbg (ehci, "port %d full speed --> companion\n",
215                         index + 1);
216
217                 // what happens if HCS_N_CC(params) == 0 ?
218                 port_status |= PORT_OWNER;
219                 port_status &= ~PORT_RWC_BITS;
220                 ehci_writel(ehci, port_status,
221                             &ehci->regs->port_status [index]);
222
223         } else
224                 ehci_dbg (ehci, "port %d high speed\n", index + 1);
225
226         return port_status;
227 }
228
229 /*-------------------------------------------------------------------------*/
230
231
232 /* build "status change" packet (one or two bytes) from HC registers */
233
234 static int
235 ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
236 {
237         struct ehci_hcd *ehci = hcd_to_ehci (hcd);
238         u32             temp, status = 0;
239         u32             mask;
240         int             ports, i, retval = 1;
241         unsigned long   flags;
242
243         /* if !USB_SUSPEND, root hub timers won't get shut down ... */
244         if (!HC_IS_RUNNING(hcd->state))
245                 return 0;
246
247         /* init status to no-changes */
248         buf [0] = 0;
249         ports = HCS_N_PORTS (ehci->hcs_params);
250         if (ports > 7) {
251                 buf [1] = 0;
252                 retval++;
253         }
254
255         /* Some boards (mostly VIA?) report bogus overcurrent indications,
256          * causing massive log spam unless we completely ignore them.  It
257          * may be relevant that VIA VT8235 controlers, where PORT_POWER is
258          * always set, seem to clear PORT_OCC and PORT_CSC when writing to
259          * PORT_POWER; that's surprising, but maybe within-spec.
260          */
261         if (!ignore_oc)
262                 mask = PORT_CSC | PORT_PEC | PORT_OCC;
263         else
264                 mask = PORT_CSC | PORT_PEC;
265         // PORT_RESUME from hardware ~= PORT_STAT_C_SUSPEND
266
267         /* no hub change reports (bit 0) for now (power, ...) */
268
269         /* port N changes (bit N)? */
270         spin_lock_irqsave (&ehci->lock, flags);
271         for (i = 0; i < ports; i++) {
272                 temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
273                 if (temp & PORT_OWNER) {
274                         /* don't report this in GetPortStatus */
275                         if (temp & PORT_CSC) {
276                                 temp &= ~PORT_RWC_BITS;
277                                 temp |= PORT_CSC;
278                                 ehci_writel(ehci, temp,
279                                             &ehci->regs->port_status [i]);
280                         }
281                         continue;
282                 }
283                 if (!(temp & PORT_CONNECT))
284                         ehci->reset_done [i] = 0;
285                 if ((temp & mask) != 0
286                                 || ((temp & PORT_RESUME) != 0
287                                         && time_after (jiffies,
288                                                 ehci->reset_done [i]))) {
289                         if (i < 7)
290                             buf [0] |= 1 << (i + 1);
291                         else
292                             buf [1] |= 1 << (i - 7);
293                         status = STS_PCD;
294                 }
295         }
296         /* FIXME autosuspend idle root hubs */
297         spin_unlock_irqrestore (&ehci->lock, flags);
298         return status ? retval : 0;
299 }
300
301 /*-------------------------------------------------------------------------*/
302
303 static void
304 ehci_hub_descriptor (
305         struct ehci_hcd                 *ehci,
306         struct usb_hub_descriptor       *desc
307 ) {
308         int             ports = HCS_N_PORTS (ehci->hcs_params);
309         u16             temp;
310
311         desc->bDescriptorType = 0x29;
312         desc->bPwrOn2PwrGood = 10;      /* ehci 1.0, 2.3.9 says 20ms max */
313         desc->bHubContrCurrent = 0;
314
315         desc->bNbrPorts = ports;
316         temp = 1 + (ports / 8);
317         desc->bDescLength = 7 + 2 * temp;
318
319         /* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
320         memset (&desc->bitmap [0], 0, temp);
321         memset (&desc->bitmap [temp], 0xff, temp);
322
323         temp = 0x0008;                  /* per-port overcurrent reporting */
324         if (HCS_PPC (ehci->hcs_params))
325                 temp |= 0x0001;         /* per-port power control */
326         else
327                 temp |= 0x0002;         /* no power switching */
328 #if 0
329 // re-enable when we support USB_PORT_FEAT_INDICATOR below.
330         if (HCS_INDICATOR (ehci->hcs_params))
331                 temp |= 0x0080;         /* per-port indicators (LEDs) */
332 #endif
333         desc->wHubCharacteristics = (__force __u16)cpu_to_le16 (temp);
334 }
335
336 /*-------------------------------------------------------------------------*/
337
338 #define PORT_WAKE_BITS  (PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E)
339
340 static int ehci_hub_control (
341         struct usb_hcd  *hcd,
342         u16             typeReq,
343         u16             wValue,
344         u16             wIndex,
345         char            *buf,
346         u16             wLength
347 ) {
348         struct ehci_hcd *ehci = hcd_to_ehci (hcd);
349         int             ports = HCS_N_PORTS (ehci->hcs_params);
350         u32             temp, status;
351         unsigned long   flags;
352         int             retval = 0;
353         unsigned        selector;
354
355         /*
356          * FIXME:  support SetPortFeatures USB_PORT_FEAT_INDICATOR.
357          * HCS_INDICATOR may say we can change LEDs to off/amber/green.
358          * (track current state ourselves) ... blink for diagnostics,
359          * power, "this is the one", etc.  EHCI spec supports this.
360          */
361
362         spin_lock_irqsave (&ehci->lock, flags);
363         switch (typeReq) {
364         case ClearHubFeature:
365                 switch (wValue) {
366                 case C_HUB_LOCAL_POWER:
367                 case C_HUB_OVER_CURRENT:
368                         /* no hub-wide feature/status flags */
369                         break;
370                 default:
371                         goto error;
372                 }
373                 break;
374         case ClearPortFeature:
375                 if (!wIndex || wIndex > ports)
376                         goto error;
377                 wIndex--;
378                 temp = ehci_readl(ehci, &ehci->regs->port_status [wIndex]);
379                 if (temp & PORT_OWNER)
380                         break;
381
382                 switch (wValue) {
383                 case USB_PORT_FEAT_ENABLE:
384                         ehci_writel(ehci, temp & ~PORT_PE,
385                                     &ehci->regs->port_status [wIndex]);
386                         break;
387                 case USB_PORT_FEAT_C_ENABLE:
388                         ehci_writel(ehci, (temp & ~PORT_RWC_BITS) | PORT_PEC,
389                                     &ehci->regs->port_status [wIndex]);
390                         break;
391                 case USB_PORT_FEAT_SUSPEND:
392                         if (temp & PORT_RESET)
393                                 goto error;
394                         if (ehci->no_selective_suspend)
395                                 break;
396                         if (temp & PORT_SUSPEND) {
397                                 if ((temp & PORT_PE) == 0)
398                                         goto error;
399                                 /* resume signaling for 20 msec */
400                                 temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
401                                 ehci_writel(ehci, temp | PORT_RESUME,
402                                             &ehci->regs->port_status [wIndex]);
403                                 ehci->reset_done [wIndex] = jiffies
404                                                 + msecs_to_jiffies (20);
405                         }
406                         break;
407                 case USB_PORT_FEAT_C_SUSPEND:
408                         /* we auto-clear this feature */
409                         break;
410                 case USB_PORT_FEAT_POWER:
411                         if (HCS_PPC (ehci->hcs_params))
412                                 ehci_writel(ehci,
413                                           temp & ~(PORT_RWC_BITS | PORT_POWER),
414                                           &ehci->regs->port_status [wIndex]);
415                         break;
416                 case USB_PORT_FEAT_C_CONNECTION:
417                         ehci_writel(ehci, (temp & ~PORT_RWC_BITS) | PORT_CSC,
418                                     &ehci->regs->port_status [wIndex]);
419                         break;
420                 case USB_PORT_FEAT_C_OVER_CURRENT:
421                         ehci_writel(ehci, (temp & ~PORT_RWC_BITS) | PORT_OCC,
422                                     &ehci->regs->port_status [wIndex]);
423                         break;
424                 case USB_PORT_FEAT_C_RESET:
425                         /* GetPortStatus clears reset */
426                         break;
427                 default:
428                         goto error;
429                 }
430                 ehci_readl(ehci, &ehci->regs->command); /* unblock posted write */
431                 break;
432         case GetHubDescriptor:
433                 ehci_hub_descriptor (ehci, (struct usb_hub_descriptor *)
434                         buf);
435                 break;
436         case GetHubStatus:
437                 /* no hub-wide feature/status flags */
438                 memset (buf, 0, 4);
439                 //cpu_to_le32s ((u32 *) buf);
440                 break;
441         case GetPortStatus:
442                 if (!wIndex || wIndex > ports)
443                         goto error;
444                 wIndex--;
445                 status = 0;
446                 temp = ehci_readl(ehci, &ehci->regs->port_status [wIndex]);
447
448                 // wPortChange bits
449                 if (temp & PORT_CSC)
450                         status |= 1 << USB_PORT_FEAT_C_CONNECTION;
451                 if (temp & PORT_PEC)
452                         status |= 1 << USB_PORT_FEAT_C_ENABLE;
453                 if ((temp & PORT_OCC) && !ignore_oc)
454                         status |= 1 << USB_PORT_FEAT_C_OVER_CURRENT;
455
456                 /* whoever resumes must GetPortStatus to complete it!! */
457                 if ((temp & PORT_RESUME)
458                                 && time_after (jiffies,
459                                         ehci->reset_done [wIndex])) {
460                         status |= 1 << USB_PORT_FEAT_C_SUSPEND;
461                         ehci->reset_done [wIndex] = 0;
462
463                         /* stop resume signaling */
464                         temp = ehci_readl(ehci,
465                                           &ehci->regs->port_status [wIndex]);
466                         ehci_writel(ehci,
467                                     temp & ~(PORT_RWC_BITS | PORT_RESUME),
468                                     &ehci->regs->port_status [wIndex]);
469                         retval = handshake(ehci,
470                                            &ehci->regs->port_status [wIndex],
471                                            PORT_RESUME, 0, 2000 /* 2msec */);
472                         if (retval != 0) {
473                                 ehci_err (ehci, "port %d resume error %d\n",
474                                         wIndex + 1, retval);
475                                 goto error;
476                         }
477                         temp &= ~(PORT_SUSPEND|PORT_RESUME|(3<<10));
478                 }
479
480                 /* whoever resets must GetPortStatus to complete it!! */
481                 if ((temp & PORT_RESET)
482                                 && time_after (jiffies,
483                                         ehci->reset_done [wIndex])) {
484                         status |= 1 << USB_PORT_FEAT_C_RESET;
485                         ehci->reset_done [wIndex] = 0;
486
487                         /* force reset to complete */
488                         ehci_writel(ehci, temp & ~(PORT_RWC_BITS | PORT_RESET),
489                                     &ehci->regs->port_status [wIndex]);
490                         /* REVISIT:  some hardware needs 550+ usec to clear
491                          * this bit; seems too long to spin routinely...
492                          */
493                         retval = handshake(ehci,
494                                            &ehci->regs->port_status [wIndex],
495                                         PORT_RESET, 0, 750);
496                         if (retval != 0) {
497                                 ehci_err (ehci, "port %d reset error %d\n",
498                                         wIndex + 1, retval);
499                                 goto error;
500                         }
501
502                         /* see what we found out */
503                         temp = check_reset_complete (ehci, wIndex,
504                                 ehci_readl(ehci,
505                                            &ehci->regs->port_status [wIndex]));
506                 }
507
508                 // don't show wPortStatus if it's owned by a companion hc
509                 if (!(temp & PORT_OWNER)) {
510                         if (temp & PORT_CONNECT) {
511                                 status |= 1 << USB_PORT_FEAT_CONNECTION;
512                                 // status may be from integrated TT
513                                 status |= ehci_port_speed(ehci, temp);
514                         }
515                         if (temp & PORT_PE)
516                                 status |= 1 << USB_PORT_FEAT_ENABLE;
517                         if (temp & (PORT_SUSPEND|PORT_RESUME))
518                                 status |= 1 << USB_PORT_FEAT_SUSPEND;
519                         if (temp & PORT_OC)
520                                 status |= 1 << USB_PORT_FEAT_OVER_CURRENT;
521                         if (temp & PORT_RESET)
522                                 status |= 1 << USB_PORT_FEAT_RESET;
523                         if (temp & PORT_POWER)
524                                 status |= 1 << USB_PORT_FEAT_POWER;
525                 }
526
527 #ifndef EHCI_VERBOSE_DEBUG
528         if (status & ~0xffff)   /* only if wPortChange is interesting */
529 #endif
530                 dbg_port (ehci, "GetStatus", wIndex + 1, temp);
531                 // we "know" this alignment is good, caller used kmalloc()...
532                 *((__le32 *) buf) = cpu_to_le32 (status);
533                 break;
534         case SetHubFeature:
535                 switch (wValue) {
536                 case C_HUB_LOCAL_POWER:
537                 case C_HUB_OVER_CURRENT:
538                         /* no hub-wide feature/status flags */
539                         break;
540                 default:
541                         goto error;
542                 }
543                 break;
544         case SetPortFeature:
545                 selector = wIndex >> 8;
546                 wIndex &= 0xff;
547                 if (!wIndex || wIndex > ports)
548                         goto error;
549                 wIndex--;
550                 temp = ehci_readl(ehci, &ehci->regs->port_status [wIndex]);
551                 if (temp & PORT_OWNER)
552                         break;
553
554                 temp &= ~PORT_RWC_BITS;
555                 switch (wValue) {
556                 case USB_PORT_FEAT_SUSPEND:
557                         if (ehci->no_selective_suspend)
558                                 break;
559                         if ((temp & PORT_PE) == 0
560                                         || (temp & PORT_RESET) != 0)
561                                 goto error;
562                         if (device_may_wakeup(&hcd->self.root_hub->dev))
563                                 temp |= PORT_WAKE_BITS;
564                         ehci_writel(ehci, temp | PORT_SUSPEND,
565                                     &ehci->regs->port_status [wIndex]);
566                         break;
567                 case USB_PORT_FEAT_POWER:
568                         if (HCS_PPC (ehci->hcs_params))
569                                 ehci_writel(ehci, temp | PORT_POWER,
570                                             &ehci->regs->port_status [wIndex]);
571                         break;
572                 case USB_PORT_FEAT_RESET:
573                         if (temp & PORT_RESUME)
574                                 goto error;
575                         /* line status bits may report this as low speed,
576                          * which can be fine if this root hub has a
577                          * transaction translator built in.
578                          */
579                         if ((temp & (PORT_PE|PORT_CONNECT)) == PORT_CONNECT
580                                         && !ehci_is_TDI(ehci)
581                                         && PORT_USB11 (temp)) {
582                                 ehci_dbg (ehci,
583                                         "port %d low speed --> companion\n",
584                                         wIndex + 1);
585                                 temp |= PORT_OWNER;
586                         } else {
587                                 ehci_vdbg (ehci, "port %d reset\n", wIndex + 1);
588                                 temp |= PORT_RESET;
589                                 temp &= ~PORT_PE;
590
591                                 /*
592                                  * caller must wait, then call GetPortStatus
593                                  * usb 2.0 spec says 50 ms resets on root
594                                  */
595                                 ehci->reset_done [wIndex] = jiffies
596                                                 + msecs_to_jiffies (50);
597                         }
598                         ehci_writel(ehci, temp,
599                                     &ehci->regs->port_status [wIndex]);
600                         break;
601
602                 /* For downstream facing ports (these):  one hub port is put
603                  * into test mode according to USB2 11.24.2.13, then the hub
604                  * must be reset (which for root hub now means rmmod+modprobe,
605                  * or else system reboot).  See EHCI 2.3.9 and 4.14 for info
606                  * about the EHCI-specific stuff.
607                  */
608                 case USB_PORT_FEAT_TEST:
609                         if (!selector || selector > 5)
610                                 goto error;
611                         ehci_quiesce(ehci);
612                         ehci_halt(ehci);
613                         temp |= selector << 16;
614                         ehci_writel(ehci, temp,
615                                     &ehci->regs->port_status [wIndex]);
616                         break;
617
618                 default:
619                         goto error;
620                 }
621                 ehci_readl(ehci, &ehci->regs->command); /* unblock posted writes */
622                 break;
623
624         default:
625 error:
626                 /* "stall" on error */
627                 retval = -EPIPE;
628         }
629         spin_unlock_irqrestore (&ehci->lock, flags);
630         return retval;
631 }