git.oblomov.eu Git - linux-2.6/blob - 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 = readl (&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 = readl (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                         writel (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         writel(mask, &ehci->regs->intr_enable);
  96         readl(&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 = readl(&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         writel(0, &ehci->regs->intr_enable);
 128
 129         /* re-init operational registers */
 130         writel(0, &ehci->regs->segment);
 131         writel(ehci->periodic_dma, &ehci->regs->frame_list);
 132         writel((u32) ehci->async->qh_dma, &ehci->regs->async_next);
 133
 134         /* restore CMD_RUN, framelist size, and irq threshold */
 135         writel (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 = readl (&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                 writel (temp, &ehci->regs->port_status [i]);
 149         }
 150         i = HCS_N_PORTS (ehci->hcs_params);
 151         mdelay (20);
 152         while (i--) {
 153                 temp = readl (&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                         writel (temp, &ehci->regs->port_status [i]);
 158                         ehci_vdbg (ehci, "resumed port %d\n", i + 1);
 159                 }
 160         }
 161         (void) readl (&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                 writel (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         writel(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                 writel (port_status, &ehci->regs->port_status [index]);
 221
 222         } else
 223                 ehci_dbg (ehci, "port %d high speed\n", index + 1);
 224
 225         return port_status;
 226 }
 227
 228 /*-------------------------------------------------------------------------*/
 229
 230
 231 /* build "status change" packet (one or two bytes) from HC registers */
 232
 233 static int
 234 ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
 235 {
 236         struct ehci_hcd *ehci = hcd_to_ehci (hcd);
 237         u32             temp, status = 0;
 238         u32             mask;
 239         int             ports, i, retval = 1;
 240         unsigned long   flags;
 241
 242         /* if !USB_SUSPEND, root hub timers won't get shut down ... */
 243         if (!HC_IS_RUNNING(hcd->state))
 244                 return 0;
 245
 246         /* init status to no-changes */
 247         buf [0] = 0;
 248         ports = HCS_N_PORTS (ehci->hcs_params);
 249         if (ports > 7) {
 250                 buf [1] = 0;
 251                 retval++;
 252         }
 253
 254         /* Some boards (mostly VIA?) report bogus overcurrent indications,
 255          * causing massive log spam unless we completely ignore them.  It
 256          * may be relevant that VIA VT8235 controlers, where PORT_POWER is
 257          * always set, seem to clear PORT_OCC and PORT_CSC when writing to
 258          * PORT_POWER; that's surprising, but maybe within-spec.
 259          */
 260         if (!ignore_oc)
 261                 mask = PORT_CSC | PORT_PEC | PORT_OCC;
 262         else
 263                 mask = PORT_CSC | PORT_PEC;
 264         // PORT_RESUME from hardware ~= PORT_STAT_C_SUSPEND
 265
 266         /* no hub change reports (bit 0) for now (power, ...) */
 267
 268         /* port N changes (bit N)? */
 269         spin_lock_irqsave (&ehci->lock, flags);
 270         for (i = 0; i < ports; i++) {
 271                 temp = readl (&ehci->regs->port_status [i]);
 272                 if (temp & PORT_OWNER) {
 273                         /* don't report this in GetPortStatus */
 274                         if (temp & PORT_CSC) {
 275                                 temp &= ~PORT_RWC_BITS;
 276                                 temp |= PORT_CSC;
 277                                 writel (temp, &ehci->regs->port_status [i]);
 278                         }
 279                         continue;
 280                 }
 281                 if (!(temp & PORT_CONNECT))
 282                         ehci->reset_done [i] = 0;
 283                 if ((temp & mask) != 0
 284                                 || ((temp & PORT_RESUME) != 0
 285                                         && time_after (jiffies,
 286                                                 ehci->reset_done [i]))) {
 287                         if (i < 7)
 288                             buf [0] |= 1 << (i + 1);
 289                         else
 290                             buf [1] |= 1 << (i - 7);
 291                         status = STS_PCD;
 292                 }
 293         }
 294         /* FIXME autosuspend idle root hubs */
 295         spin_unlock_irqrestore (&ehci->lock, flags);
 296         return status ? retval : 0;
 297 }
 298
 299 /*-------------------------------------------------------------------------*/
 300
 301 static void
 302 ehci_hub_descriptor (
 303         struct ehci_hcd                 *ehci,
 304         struct usb_hub_descriptor       *desc
 305 ) {
 306         int             ports = HCS_N_PORTS (ehci->hcs_params);
 307         u16             temp;
 308
 309         desc->bDescriptorType = 0x29;
 310         desc->bPwrOn2PwrGood = 10;      /* ehci 1.0, 2.3.9 says 20ms max */
 311         desc->bHubContrCurrent = 0;
 312
 313         desc->bNbrPorts = ports;
 314         temp = 1 + (ports / 8);
 315         desc->bDescLength = 7 + 2 * temp;
 316
 317         /* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
 318         memset (&desc->bitmap [0], 0, temp);
 319         memset (&desc->bitmap [temp], 0xff, temp);
 320
 321         temp = 0x0008;                  /* per-port overcurrent reporting */
 322         if (HCS_PPC (ehci->hcs_params))
 323                 temp |= 0x0001;         /* per-port power control */
 324         else
 325                 temp |= 0x0002;         /* no power switching */
 326 #if 0
 327 // re-enable when we support USB_PORT_FEAT_INDICATOR below.
 328         if (HCS_INDICATOR (ehci->hcs_params))
 329                 temp |= 0x0080;         /* per-port indicators (LEDs) */
 330 #endif
 331         desc->wHubCharacteristics = (__force __u16)cpu_to_le16 (temp);
 332 }
 333
 334 /*-------------------------------------------------------------------------*/
 335
 336 #define PORT_WAKE_BITS  (PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E)
 337
 338 static int ehci_hub_control (
 339         struct usb_hcd  *hcd,
 340         u16             typeReq,
 341         u16             wValue,
 342         u16             wIndex,
 343         char            *buf,
 344         u16             wLength
 345 ) {
 346         struct ehci_hcd *ehci = hcd_to_ehci (hcd);
 347         int             ports = HCS_N_PORTS (ehci->hcs_params);
 348         u32             temp, status;
 349         unsigned long   flags;
 350         int             retval = 0;
 351         unsigned        selector;
 352
 353         /*
 354          * FIXME:  support SetPortFeatures USB_PORT_FEAT_INDICATOR.
 355          * HCS_INDICATOR may say we can change LEDs to off/amber/green.
 356          * (track current state ourselves) ... blink for diagnostics,
 357          * power, "this is the one", etc.  EHCI spec supports this.
 358          */
 359
 360         spin_lock_irqsave (&ehci->lock, flags);
 361         switch (typeReq) {
 362         case ClearHubFeature:
 363                 switch (wValue) {
 364                 case C_HUB_LOCAL_POWER:
 365                 case C_HUB_OVER_CURRENT:
 366                         /* no hub-wide feature/status flags */
 367                         break;
 368                 default:
 369                         goto error;
 370                 }
 371                 break;
 372         case ClearPortFeature:
 373                 if (!wIndex || wIndex > ports)
 374                         goto error;
 375                 wIndex--;
 376                 temp = readl (&ehci->regs->port_status [wIndex]);
 377                 if (temp & PORT_OWNER)
 378                         break;
 379
 380                 switch (wValue) {
 381                 case USB_PORT_FEAT_ENABLE:
 382                         writel (temp & ~PORT_PE,
 383                                 &ehci->regs->port_status [wIndex]);
 384                         break;
 385                 case USB_PORT_FEAT_C_ENABLE:
 386                         writel((temp & ~PORT_RWC_BITS) | PORT_PEC,
 387                                 &ehci->regs->port_status [wIndex]);
 388                         break;
 389                 case USB_PORT_FEAT_SUSPEND:
 390                         if (temp & PORT_RESET)
 391                                 goto error;
 392                         if (ehci->no_selective_suspend)
 393                                 break;
 394                         if (temp & PORT_SUSPEND) {
 395                                 if ((temp & PORT_PE) == 0)
 396                                         goto error;
 397                                 /* resume signaling for 20 msec */
 398                                 temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
 399                                 writel (temp | PORT_RESUME,
 400                                         &ehci->regs->port_status [wIndex]);
 401                                 ehci->reset_done [wIndex] = jiffies
 402                                                 + msecs_to_jiffies (20);
 403                         }
 404                         break;
 405                 case USB_PORT_FEAT_C_SUSPEND:
 406                         /* we auto-clear this feature */
 407                         break;
 408                 case USB_PORT_FEAT_POWER:
 409                         if (HCS_PPC (ehci->hcs_params))
 410                                 writel (temp & ~(PORT_RWC_BITS | PORT_POWER),
 411                                         &ehci->regs->port_status [wIndex]);
 412                         break;
 413                 case USB_PORT_FEAT_C_CONNECTION:
 414                         writel((temp & ~PORT_RWC_BITS) | PORT_CSC,
 415                                 &ehci->regs->port_status [wIndex]);
 416                         break;
 417                 case USB_PORT_FEAT_C_OVER_CURRENT:
 418                         writel((temp & ~PORT_RWC_BITS) | PORT_OCC,
 419                                 &ehci->regs->port_status [wIndex]);
 420                         break;
 421                 case USB_PORT_FEAT_C_RESET:
 422                         /* GetPortStatus clears reset */
 423                         break;
 424                 default:
 425                         goto error;
 426                 }
 427                 readl (&ehci->regs->command);   /* unblock posted write */
 428                 break;
 429         case GetHubDescriptor:
 430                 ehci_hub_descriptor (ehci, (struct usb_hub_descriptor *)
 431                         buf);
 432                 break;
 433         case GetHubStatus:
 434                 /* no hub-wide feature/status flags */
 435                 memset (buf, 0, 4);
 436                 //cpu_to_le32s ((u32 *) buf);
 437                 break;
 438         case GetPortStatus:
 439                 if (!wIndex || wIndex > ports)
 440                         goto error;
 441                 wIndex--;
 442                 status = 0;
 443                 temp = readl (&ehci->regs->port_status [wIndex]);
 444
 445                 // wPortChange bits
 446                 if (temp & PORT_CSC)
 447                         status |= 1 << USB_PORT_FEAT_C_CONNECTION;
 448                 if (temp & PORT_PEC)
 449                         status |= 1 << USB_PORT_FEAT_C_ENABLE;
 450                 if ((temp & PORT_OCC) && !ignore_oc)
 451                         status |= 1 << USB_PORT_FEAT_C_OVER_CURRENT;
 452
 453                 /* whoever resumes must GetPortStatus to complete it!! */
 454                 if ((temp & PORT_RESUME)
 455                                 && time_after (jiffies,
 456                                         ehci->reset_done [wIndex])) {
 457                         status |= 1 << USB_PORT_FEAT_C_SUSPEND;
 458                         ehci->reset_done [wIndex] = 0;
 459
 460                         /* stop resume signaling */
 461                         temp = readl (&ehci->regs->port_status [wIndex]);
 462                         writel (temp & ~(PORT_RWC_BITS | PORT_RESUME),
 463                                 &ehci->regs->port_status [wIndex]);
 464                         retval = handshake (
 465                                         &ehci->regs->port_status [wIndex],
 466                                         PORT_RESUME, 0, 2000 /* 2msec */);
 467                         if (retval != 0) {
 468                                 ehci_err (ehci, "port %d resume error %d\n",
 469                                         wIndex + 1, retval);
 470                                 goto error;
 471                         }
 472                         temp &= ~(PORT_SUSPEND|PORT_RESUME|(3<<10));
 473                 }
 474
 475                 /* whoever resets must GetPortStatus to complete it!! */
 476                 if ((temp & PORT_RESET)
 477                                 && time_after (jiffies,
 478                                         ehci->reset_done [wIndex])) {
 479                         status |= 1 << USB_PORT_FEAT_C_RESET;
 480                         ehci->reset_done [wIndex] = 0;
 481
 482                         /* force reset to complete */
 483                         writel (temp & ~(PORT_RWC_BITS | PORT_RESET),
 484                                         &ehci->regs->port_status [wIndex]);
 485                         /* REVISIT:  some hardware needs 550+ usec to clear
 486                          * this bit; seems too long to spin routinely...
 487                          */
 488                         retval = handshake (
 489                                         &ehci->regs->port_status [wIndex],
 490                                         PORT_RESET, 0, 750);
 491                         if (retval != 0) {
 492                                 ehci_err (ehci, "port %d reset error %d\n",
 493                                         wIndex + 1, retval);
 494                                 goto error;
 495                         }
 496
 497                         /* see what we found out */
 498                         temp = check_reset_complete (ehci, wIndex,
 499                                 readl (&ehci->regs->port_status [wIndex]));
 500                 }
 501
 502                 // don't show wPortStatus if it's owned by a companion hc
 503                 if (!(temp & PORT_OWNER)) {
 504                         if (temp & PORT_CONNECT) {
 505                                 status |= 1 << USB_PORT_FEAT_CONNECTION;
 506                                 // status may be from integrated TT
 507                                 status |= ehci_port_speed(ehci, temp);
 508                         }
 509                         if (temp & PORT_PE)
 510                                 status |= 1 << USB_PORT_FEAT_ENABLE;
 511                         if (temp & (PORT_SUSPEND|PORT_RESUME))
 512                                 status |= 1 << USB_PORT_FEAT_SUSPEND;
 513                         if (temp & PORT_OC)
 514                                 status |= 1 << USB_PORT_FEAT_OVER_CURRENT;
 515                         if (temp & PORT_RESET)
 516                                 status |= 1 << USB_PORT_FEAT_RESET;
 517                         if (temp & PORT_POWER)
 518                                 status |= 1 << USB_PORT_FEAT_POWER;
 519                 }
 520
 521 #ifndef EHCI_VERBOSE_DEBUG
 522         if (status & ~0xffff)   /* only if wPortChange is interesting */
 523 #endif
 524                 dbg_port (ehci, "GetStatus", wIndex + 1, temp);
 525                 // we "know" this alignment is good, caller used kmalloc()...
 526                 *((__le32 *) buf) = cpu_to_le32 (status);
 527                 break;
 528         case SetHubFeature:
 529                 switch (wValue) {
 530                 case C_HUB_LOCAL_POWER:
 531                 case C_HUB_OVER_CURRENT:
 532                         /* no hub-wide feature/status flags */
 533                         break;
 534                 default:
 535                         goto error;
 536                 }
 537                 break;
 538         case SetPortFeature:
 539                 selector = wIndex >> 8;
 540                 wIndex &= 0xff;
 541                 if (!wIndex || wIndex > ports)
 542                         goto error;
 543                 wIndex--;
 544                 temp = readl (&ehci->regs->port_status [wIndex]);
 545                 if (temp & PORT_OWNER)
 546                         break;
 547
 548                 temp &= ~PORT_RWC_BITS;
 549                 switch (wValue) {
 550                 case USB_PORT_FEAT_SUSPEND:
 551                         if (ehci->no_selective_suspend)
 552                                 break;
 553                         if ((temp & PORT_PE) == 0
 554                                         || (temp & PORT_RESET) != 0)
 555                                 goto error;
 556                         if (device_may_wakeup(&hcd->self.root_hub->dev))
 557                                 temp |= PORT_WAKE_BITS;
 558                         writel (temp | PORT_SUSPEND,
 559                                 &ehci->regs->port_status [wIndex]);
 560                         break;
 561                 case USB_PORT_FEAT_POWER:
 562                         if (HCS_PPC (ehci->hcs_params))
 563                                 writel (temp | PORT_POWER,
 564                                         &ehci->regs->port_status [wIndex]);
 565                         break;
 566                 case USB_PORT_FEAT_RESET:
 567                         if (temp & PORT_RESUME)
 568                                 goto error;
 569                         /* line status bits may report this as low speed,
 570                          * which can be fine if this root hub has a
 571                          * transaction translator built in.
 572                          */
 573                         if ((temp & (PORT_PE|PORT_CONNECT)) == PORT_CONNECT
 574                                         && !ehci_is_TDI(ehci)
 575                                         && PORT_USB11 (temp)) {
 576                                 ehci_dbg (ehci,
 577                                         "port %d low speed --> companion\n",
 578                                         wIndex + 1);
 579                                 temp |= PORT_OWNER;
 580                         } else {
 581                                 ehci_vdbg (ehci, "port %d reset\n", wIndex + 1);
 582                                 temp |= PORT_RESET;
 583                                 temp &= ~PORT_PE;
 584
 585                                 /*
 586                                  * caller must wait, then call GetPortStatus
 587                                  * usb 2.0 spec says 50 ms resets on root
 588                                  */
 589                                 ehci->reset_done [wIndex] = jiffies
 590                                                 + msecs_to_jiffies (50);
 591                         }
 592                         writel (temp, &ehci->regs->port_status [wIndex]);
 593                         break;
 594
 595                 /* For downstream facing ports (these):  one hub port is put
 596                  * into test mode according to USB2 11.24.2.13, then the hub
 597                  * must be reset (which for root hub now means rmmod+modprobe,
 598                  * or else system reboot).  See EHCI 2.3.9 and 4.14 for info
 599                  * about the EHCI-specific stuff.
 600                  */
 601                 case USB_PORT_FEAT_TEST:
 602                         if (!selector || selector > 5)
 603                                 goto error;
 604                         ehci_quiesce(ehci);
 605                         ehci_halt(ehci);
 606                         temp |= selector << 16;
 607                         writel (temp, &ehci->regs->port_status [wIndex]);
 608                         break;
 609
 610                 default:
 611                         goto error;
 612                 }
 613                 readl (&ehci->regs->command);   /* unblock posted writes */
 614                 break;
 615
 616         default:
 617 error:
 618                 /* "stall" on error */
 619                 retval = -EPIPE;
 620         }
 621         spin_unlock_irqrestore (&ehci->lock, flags);
 622         return retval;
 623 }