git.oblomov.eu Git - linux-2.6/blob - drivers/usb/host/ohci-q.c

   1 /*
   2  * OHCI HCD (Host Controller Driver) for USB.
   3  *
   4  * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
   5  * (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
   6  *
   7  * This file is licenced under the GPL.
   8  */
   9
  10 #include <linux/irq.h>
  11
  12 static void urb_free_priv (struct ohci_hcd *hc, urb_priv_t *urb_priv)
  13 {
  14         int             last = urb_priv->length - 1;
  15
  16         if (last >= 0) {
  17                 int             i;
  18                 struct td       *td;
  19
  20                 for (i = 0; i <= last; i++) {
  21                         td = urb_priv->td [i];
  22                         if (td)
  23                                 td_free (hc, td);
  24                 }
  25         }
  26
  27         list_del (&urb_priv->pending);
  28         kfree (urb_priv);
  29 }
  30
  31 /*-------------------------------------------------------------------------*/
  32
  33 /*
  34  * URB goes back to driver, and isn't reissued.
  35  * It's completely gone from HC data structures.
  36  * PRECONDITION:  ohci lock held, irqs blocked.
  37  */
  38 static void
  39 finish_urb (struct ohci_hcd *ohci, struct urb *urb)
  40 __releases(ohci->lock)
  41 __acquires(ohci->lock)
  42 {
  43         // ASSERT (urb->hcpriv != 0);
  44
  45         urb_free_priv (ohci, urb->hcpriv);
  46         urb->hcpriv = NULL;
  47
  48         spin_lock (&urb->lock);
  49         if (likely (urb->status == -EINPROGRESS))
  50                 urb->status = 0;
  51         /* report short control reads right even though the data TD always
  52          * has TD_R set.  (much simpler, but creates the 1-td limit.)
  53          */
  54         if (unlikely (urb->transfer_flags & URB_SHORT_NOT_OK)
  55                         && unlikely (usb_pipecontrol (urb->pipe))
  56                         && urb->actual_length < urb->transfer_buffer_length
  57                         && usb_pipein (urb->pipe)
  58                         && urb->status == 0) {
  59                 urb->status = -EREMOTEIO;
  60         }
  61         spin_unlock (&urb->lock);
  62
  63         switch (usb_pipetype (urb->pipe)) {
  64         case PIPE_ISOCHRONOUS:
  65                 ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs--;
  66                 break;
  67         case PIPE_INTERRUPT:
  68                 ohci_to_hcd(ohci)->self.bandwidth_int_reqs--;
  69                 break;
  70         }
  71
  72 #ifdef OHCI_VERBOSE_DEBUG
  73         urb_print (urb, "RET", usb_pipeout (urb->pipe));
  74 #endif
  75
  76         /* urb->complete() can reenter this HCD */
  77         spin_unlock (&ohci->lock);
  78         usb_hcd_giveback_urb (ohci_to_hcd(ohci), urb);
  79         spin_lock (&ohci->lock);
  80
  81         /* stop periodic dma if it's not needed */
  82         if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0
  83                         && ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0) {
  84                 ohci->hc_control &= ~(OHCI_CTRL_PLE|OHCI_CTRL_IE);
  85                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
  86         }
  87 }
  88
  89
  90 /*-------------------------------------------------------------------------*
  91  * ED handling functions
  92  *-------------------------------------------------------------------------*/
  93
  94 /* search for the right schedule branch to use for a periodic ed.
  95  * does some load balancing; returns the branch, or negative errno.
  96  */
  97 static int balance (struct ohci_hcd *ohci, int interval, int load)
  98 {
  99         int     i, branch = -ENOSPC;
 100
 101         /* iso periods can be huge; iso tds specify frame numbers */
 102         if (interval > NUM_INTS)
 103                 interval = NUM_INTS;
 104
 105         /* search for the least loaded schedule branch of that period
 106          * that has enough bandwidth left unreserved.
 107          */
 108         for (i = 0; i < interval ; i++) {
 109                 if (branch < 0 || ohci->load [branch] > ohci->load [i]) {
 110                         int     j;
 111
 112                         /* usb 1.1 says 90% of one frame */
 113                         for (j = i; j < NUM_INTS; j += interval) {
 114                                 if ((ohci->load [j] + load) > 900)
 115                                         break;
 116                         }
 117                         if (j < NUM_INTS)
 118                                 continue;
 119                         branch = i;
 120                 }
 121         }
 122         return branch;
 123 }
 124
 125 /*-------------------------------------------------------------------------*/
 126
 127 /* both iso and interrupt requests have periods; this routine puts them
 128  * into the schedule tree in the apppropriate place.  most iso devices use
 129  * 1msec periods, but that's not required.
 130  */
 131 static void periodic_link (struct ohci_hcd *ohci, struct ed *ed)
 132 {
 133         unsigned        i;
 134
 135         ohci_vdbg (ohci, "link %sed %p branch %d [%dus.], interval %d\n",
 136                 (ed->hwINFO & cpu_to_hc32 (ohci, ED_ISO)) ? "iso " : "",
 137                 ed, ed->branch, ed->load, ed->interval);
 138
 139         for (i = ed->branch; i < NUM_INTS; i += ed->interval) {
 140                 struct ed       **prev = &ohci->periodic [i];
 141                 __hc32          *prev_p = &ohci->hcca->int_table [i];
 142                 struct ed       *here = *prev;
 143
 144                 /* sorting each branch by period (slow before fast)
 145                  * lets us share the faster parts of the tree.
 146                  * (plus maybe: put interrupt eds before iso)
 147                  */
 148                 while (here && ed != here) {
 149                         if (ed->interval > here->interval)
 150                                 break;
 151                         prev = &here->ed_next;
 152                         prev_p = &here->hwNextED;
 153                         here = *prev;
 154                 }
 155                 if (ed != here) {
 156                         ed->ed_next = here;
 157                         if (here)
 158                                 ed->hwNextED = *prev_p;
 159                         wmb ();
 160                         *prev = ed;
 161                         *prev_p = cpu_to_hc32(ohci, ed->dma);
 162                         wmb();
 163                 }
 164                 ohci->load [i] += ed->load;
 165         }
 166         ohci_to_hcd(ohci)->self.bandwidth_allocated += ed->load / ed->interval;
 167 }
 168
 169 /* link an ed into one of the HC chains */
 170
 171 static int ed_schedule (struct ohci_hcd *ohci, struct ed *ed)
 172 {
 173         int     branch;
 174
 175         if (ohci_to_hcd(ohci)->state == HC_STATE_QUIESCING)
 176                 return -EAGAIN;
 177
 178         ed->state = ED_OPER;
 179         ed->ed_prev = NULL;
 180         ed->ed_next = NULL;
 181         ed->hwNextED = 0;
 182         wmb ();
 183
 184         /* we care about rm_list when setting CLE/BLE in case the HC was at
 185          * work on some TD when CLE/BLE was turned off, and isn't quiesced
 186          * yet.  finish_unlinks() restarts as needed, some upcoming INTR_SF.
 187          *
 188          * control and bulk EDs are doubly linked (ed_next, ed_prev), but
 189          * periodic ones are singly linked (ed_next). that's because the
 190          * periodic schedule encodes a tree like figure 3-5 in the ohci
 191          * spec:  each qh can have several "previous" nodes, and the tree
 192          * doesn't have unused/idle descriptors.
 193          */
 194         switch (ed->type) {
 195         case PIPE_CONTROL:
 196                 if (ohci->ed_controltail == NULL) {
 197                         WARN_ON (ohci->hc_control & OHCI_CTRL_CLE);
 198                         ohci_writel (ohci, ed->dma,
 199                                         &ohci->regs->ed_controlhead);
 200                 } else {
 201                         ohci->ed_controltail->ed_next = ed;
 202                         ohci->ed_controltail->hwNextED = cpu_to_hc32 (ohci,
 203                                                                 ed->dma);
 204                 }
 205                 ed->ed_prev = ohci->ed_controltail;
 206                 if (!ohci->ed_controltail && !ohci->ed_rm_list) {
 207                         wmb();
 208                         ohci->hc_control |= OHCI_CTRL_CLE;
 209                         ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
 210                         ohci_writel (ohci, ohci->hc_control,
 211                                         &ohci->regs->control);
 212                 }
 213                 ohci->ed_controltail = ed;
 214                 break;
 215
 216         case PIPE_BULK:
 217                 if (ohci->ed_bulktail == NULL) {
 218                         WARN_ON (ohci->hc_control & OHCI_CTRL_BLE);
 219                         ohci_writel (ohci, ed->dma, &ohci->regs->ed_bulkhead);
 220                 } else {
 221                         ohci->ed_bulktail->ed_next = ed;
 222                         ohci->ed_bulktail->hwNextED = cpu_to_hc32 (ohci,
 223                                                                 ed->dma);
 224                 }
 225                 ed->ed_prev = ohci->ed_bulktail;
 226                 if (!ohci->ed_bulktail && !ohci->ed_rm_list) {
 227                         wmb();
 228                         ohci->hc_control |= OHCI_CTRL_BLE;
 229                         ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
 230                         ohci_writel (ohci, ohci->hc_control,
 231                                         &ohci->regs->control);
 232                 }
 233                 ohci->ed_bulktail = ed;
 234                 break;
 235
 236         // case PIPE_INTERRUPT:
 237         // case PIPE_ISOCHRONOUS:
 238         default:
 239                 branch = balance (ohci, ed->interval, ed->load);
 240                 if (branch < 0) {
 241                         ohci_dbg (ohci,
 242                                 "ERR %d, interval %d msecs, load %d\n",
 243                                 branch, ed->interval, ed->load);
 244                         // FIXME if there are TDs queued, fail them!
 245                         return branch;
 246                 }
 247                 ed->branch = branch;
 248                 periodic_link (ohci, ed);
 249         }
 250
 251         /* the HC may not see the schedule updates yet, but if it does
 252          * then they'll be properly ordered.
 253          */
 254         return 0;
 255 }
 256
 257 /*-------------------------------------------------------------------------*/
 258
 259 /* scan the periodic table to find and unlink this ED */
 260 static void periodic_unlink (struct ohci_hcd *ohci, struct ed *ed)
 261 {
 262         int     i;
 263
 264         for (i = ed->branch; i < NUM_INTS; i += ed->interval) {
 265                 struct ed       *temp;
 266                 struct ed       **prev = &ohci->periodic [i];
 267                 __hc32          *prev_p = &ohci->hcca->int_table [i];
 268
 269                 while (*prev && (temp = *prev) != ed) {
 270                         prev_p = &temp->hwNextED;
 271                         prev = &temp->ed_next;
 272                 }
 273                 if (*prev) {
 274                         *prev_p = ed->hwNextED;
 275                         *prev = ed->ed_next;
 276                 }
 277                 ohci->load [i] -= ed->load;
 278         }
 279         ohci_to_hcd(ohci)->self.bandwidth_allocated -= ed->load / ed->interval;
 280
 281         ohci_vdbg (ohci, "unlink %sed %p branch %d [%dus.], interval %d\n",
 282                 (ed->hwINFO & cpu_to_hc32 (ohci, ED_ISO)) ? "iso " : "",
 283                 ed, ed->branch, ed->load, ed->interval);
 284 }
 285
 286 /* unlink an ed from one of the HC chains.
 287  * just the link to the ed is unlinked.
 288  * the link from the ed still points to another operational ed or 0
 289  * so the HC can eventually finish the processing of the unlinked ed
 290  * (assuming it already started that, which needn't be true).
 291  *
 292  * ED_UNLINK is a transient state: the HC may still see this ED, but soon
 293  * it won't.  ED_SKIP means the HC will finish its current transaction,
 294  * but won't start anything new.  The TD queue may still grow; device
 295  * drivers don't know about this HCD-internal state.
 296  *
 297  * When the HC can't see the ED, something changes ED_UNLINK to one of:
 298  *
 299  *  - ED_OPER: when there's any request queued, the ED gets rescheduled
 300  *    immediately.  HC should be working on them.
 301  *
 302  *  - ED_IDLE:  when there's no TD queue. there's no reason for the HC
 303  *    to care about this ED; safe to disable the endpoint.
 304  *
 305  * When finish_unlinks() runs later, after SOF interrupt, it will often
 306  * complete one or more URB unlinks before making that state change.
 307  */
 308 static void ed_deschedule (struct ohci_hcd *ohci, struct ed *ed)
 309 {
 310         ed->hwINFO |= cpu_to_hc32 (ohci, ED_SKIP);
 311         wmb ();
 312         ed->state = ED_UNLINK;
 313
 314         /* To deschedule something from the control or bulk list, just
 315          * clear CLE/BLE and wait.  There's no safe way to scrub out list
 316          * head/current registers until later, and "later" isn't very
 317          * tightly specified.  Figure 6-5 and Section 6.4.2.2 show how
 318          * the HC is reading the ED queues (while we modify them).
 319          *
 320          * For now, ed_schedule() is "later".  It might be good paranoia
 321          * to scrub those registers in finish_unlinks(), in case of bugs
 322          * that make the HC try to use them.
 323          */
 324         switch (ed->type) {
 325         case PIPE_CONTROL:
 326                 /* remove ED from the HC's list: */
 327                 if (ed->ed_prev == NULL) {
 328                         if (!ed->hwNextED) {
 329                                 ohci->hc_control &= ~OHCI_CTRL_CLE;
 330                                 ohci_writel (ohci, ohci->hc_control,
 331                                                 &ohci->regs->control);
 332                                 // a ohci_readl() later syncs CLE with the HC
 333                         } else
 334                                 ohci_writel (ohci,
 335                                         hc32_to_cpup (ohci, &ed->hwNextED),
 336                                         &ohci->regs->ed_controlhead);
 337                 } else {
 338                         ed->ed_prev->ed_next = ed->ed_next;
 339                         ed->ed_prev->hwNextED = ed->hwNextED;
 340                 }
 341                 /* remove ED from the HCD's list: */
 342                 if (ohci->ed_controltail == ed) {
 343                         ohci->ed_controltail = ed->ed_prev;
 344                         if (ohci->ed_controltail)
 345                                 ohci->ed_controltail->ed_next = NULL;
 346                 } else if (ed->ed_next) {
 347                         ed->ed_next->ed_prev = ed->ed_prev;
 348                 }
 349                 break;
 350
 351         case PIPE_BULK:
 352                 /* remove ED from the HC's list: */
 353                 if (ed->ed_prev == NULL) {
 354                         if (!ed->hwNextED) {
 355                                 ohci->hc_control &= ~OHCI_CTRL_BLE;
 356                                 ohci_writel (ohci, ohci->hc_control,
 357                                                 &ohci->regs->control);
 358                                 // a ohci_readl() later syncs BLE with the HC
 359                         } else
 360                                 ohci_writel (ohci,
 361                                         hc32_to_cpup (ohci, &ed->hwNextED),
 362                                         &ohci->regs->ed_bulkhead);
 363                 } else {
 364                         ed->ed_prev->ed_next = ed->ed_next;
 365                         ed->ed_prev->hwNextED = ed->hwNextED;
 366                 }
 367                 /* remove ED from the HCD's list: */
 368                 if (ohci->ed_bulktail == ed) {
 369                         ohci->ed_bulktail = ed->ed_prev;
 370                         if (ohci->ed_bulktail)
 371                                 ohci->ed_bulktail->ed_next = NULL;
 372                 } else if (ed->ed_next) {
 373                         ed->ed_next->ed_prev = ed->ed_prev;
 374                 }
 375                 break;
 376
 377         // case PIPE_INTERRUPT:
 378         // case PIPE_ISOCHRONOUS:
 379         default:
 380                 periodic_unlink (ohci, ed);
 381                 break;
 382         }
 383 }
 384
 385
 386 /*-------------------------------------------------------------------------*/
 387
 388 /* get and maybe (re)init an endpoint. init _should_ be done only as part
 389  * of enumeration, usb_set_configuration() or usb_set_interface().
 390  */
 391 static struct ed *ed_get (
 392         struct ohci_hcd         *ohci,
 393         struct usb_host_endpoint *ep,
 394         struct usb_device       *udev,
 395         unsigned int            pipe,
 396         int                     interval
 397 ) {
 398         struct ed               *ed;
 399         unsigned long           flags;
 400
 401         spin_lock_irqsave (&ohci->lock, flags);
 402
 403         if (!(ed = ep->hcpriv)) {
 404                 struct td       *td;
 405                 int             is_out;
 406                 u32             info;
 407
 408                 ed = ed_alloc (ohci, GFP_ATOMIC);
 409                 if (!ed) {
 410                         /* out of memory */
 411                         goto done;
 412                 }
 413
 414                 /* dummy td; end of td list for ed */
 415                 td = td_alloc (ohci, GFP_ATOMIC);
 416                 if (!td) {
 417                         /* out of memory */
 418                         ed_free (ohci, ed);
 419                         ed = NULL;
 420                         goto done;
 421                 }
 422                 ed->dummy = td;
 423                 ed->hwTailP = cpu_to_hc32 (ohci, td->td_dma);
 424                 ed->hwHeadP = ed->hwTailP;      /* ED_C, ED_H zeroed */
 425                 ed->state = ED_IDLE;
 426
 427                 is_out = !(ep->desc.bEndpointAddress & USB_DIR_IN);
 428
 429                 /* FIXME usbcore changes dev->devnum before SET_ADDRESS
 430                  * suceeds ... otherwise we wouldn't need "pipe".
 431                  */
 432                 info = usb_pipedevice (pipe);
 433                 ed->type = usb_pipetype(pipe);
 434
 435                 info |= (ep->desc.bEndpointAddress & ~USB_DIR_IN) << 7;
 436                 info |= le16_to_cpu(ep->desc.wMaxPacketSize) << 16;
 437                 if (udev->speed == USB_SPEED_LOW)
 438                         info |= ED_LOWSPEED;
 439                 /* only control transfers store pids in tds */
 440                 if (ed->type != PIPE_CONTROL) {
 441                         info |= is_out ? ED_OUT : ED_IN;
 442                         if (ed->type != PIPE_BULK) {
 443                                 /* periodic transfers... */
 444                                 if (ed->type == PIPE_ISOCHRONOUS)
 445                                         info |= ED_ISO;
 446                                 else if (interval > 32) /* iso can be bigger */
 447                                         interval = 32;
 448                                 ed->interval = interval;
 449                                 ed->load = usb_calc_bus_time (
 450                                         udev->speed, !is_out,
 451                                         ed->type == PIPE_ISOCHRONOUS,
 452                                         le16_to_cpu(ep->desc.wMaxPacketSize))
 453                                                 / 1000;
 454                         }
 455                 }
 456                 ed->hwINFO = cpu_to_hc32(ohci, info);
 457
 458                 ep->hcpriv = ed;
 459         }
 460
 461 done:
 462         spin_unlock_irqrestore (&ohci->lock, flags);
 463         return ed;
 464 }
 465
 466 /*-------------------------------------------------------------------------*/
 467
 468 /* request unlinking of an endpoint from an operational HC.
 469  * put the ep on the rm_list
 470  * real work is done at the next start frame (SF) hardware interrupt
 471  * caller guarantees HCD is running, so hardware access is safe,
 472  * and that ed->state is ED_OPER
 473  */
 474 static void start_ed_unlink (struct ohci_hcd *ohci, struct ed *ed)
 475 {
 476         ed->hwINFO |= cpu_to_hc32 (ohci, ED_DEQUEUE);
 477         ed_deschedule (ohci, ed);
 478
 479         /* rm_list is just singly linked, for simplicity */
 480         ed->ed_next = ohci->ed_rm_list;
 481         ed->ed_prev = NULL;
 482         ohci->ed_rm_list = ed;
 483
 484         /* enable SOF interrupt */
 485         ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);
 486         ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
 487         // flush those writes, and get latest HCCA contents
 488         (void) ohci_readl (ohci, &ohci->regs->control);
 489
 490         /* SF interrupt might get delayed; record the frame counter value that
 491          * indicates when the HC isn't looking at it, so concurrent unlinks
 492          * behave.  frame_no wraps every 2^16 msec, and changes right before
 493          * SF is triggered.
 494          */
 495         ed->tick = ohci_frame_no(ohci) + 1;
 496
 497 }
 498
 499 /*-------------------------------------------------------------------------*
 500  * TD handling functions
 501  *-------------------------------------------------------------------------*/
 502
 503 /* enqueue next TD for this URB (OHCI spec 5.2.8.2) */
 504
 505 static void
 506 td_fill (struct ohci_hcd *ohci, u32 info,
 507         dma_addr_t data, int len,
 508         struct urb *urb, int index)
 509 {
 510         struct td               *td, *td_pt;
 511         struct urb_priv         *urb_priv = urb->hcpriv;
 512         int                     is_iso = info & TD_ISO;
 513         int                     hash;
 514
 515         // ASSERT (index < urb_priv->length);
 516
 517         /* aim for only one interrupt per urb.  mostly applies to control
 518          * and iso; other urbs rarely need more than one TD per urb.
 519          * this way, only final tds (or ones with an error) cause IRQs.
 520          * at least immediately; use DI=6 in case any control request is
 521          * tempted to die part way through.  (and to force the hc to flush
 522          * its donelist soonish, even on unlink paths.)
 523          *
 524          * NOTE: could delay interrupts even for the last TD, and get fewer
 525          * interrupts ... increasing per-urb latency by sharing interrupts.
 526          * Drivers that queue bulk urbs may request that behavior.
 527          */
 528         if (index != (urb_priv->length - 1)
 529                         || (urb->transfer_flags & URB_NO_INTERRUPT))
 530                 info |= TD_DI_SET (6);
 531
 532         /* use this td as the next dummy */
 533         td_pt = urb_priv->td [index];
 534
 535         /* fill the old dummy TD */
 536         td = urb_priv->td [index] = urb_priv->ed->dummy;
 537         urb_priv->ed->dummy = td_pt;
 538
 539         td->ed = urb_priv->ed;
 540         td->next_dl_td = NULL;
 541         td->index = index;
 542         td->urb = urb;
 543         td->data_dma = data;
 544         if (!len)
 545                 data = 0;
 546
 547         td->hwINFO = cpu_to_hc32 (ohci, info);
 548         if (is_iso) {
 549                 td->hwCBP = cpu_to_hc32 (ohci, data & 0xFFFFF000);
 550                 *ohci_hwPSWp(ohci, td, 0) = cpu_to_hc16 (ohci,
 551                                                 (data & 0x0FFF) | 0xE000);
 552                 td->ed->last_iso = info & 0xffff;
 553         } else {
 554                 td->hwCBP = cpu_to_hc32 (ohci, data);
 555         }
 556         if (data)
 557                 td->hwBE = cpu_to_hc32 (ohci, data + len - 1);
 558         else
 559                 td->hwBE = 0;
 560         td->hwNextTD = cpu_to_hc32 (ohci, td_pt->td_dma);
 561
 562         /* append to queue */
 563         list_add_tail (&td->td_list, &td->ed->td_list);
 564
 565         /* hash it for later reverse mapping */
 566         hash = TD_HASH_FUNC (td->td_dma);
 567         td->td_hash = ohci->td_hash [hash];
 568         ohci->td_hash [hash] = td;
 569
 570         /* HC might read the TD (or cachelines) right away ... */
 571         wmb ();
 572         td->ed->hwTailP = td->hwNextTD;
 573 }
 574
 575 /*-------------------------------------------------------------------------*/
 576
 577 /* Prepare all TDs of a transfer, and queue them onto the ED.
 578  * Caller guarantees HC is active.
 579  * Usually the ED is already on the schedule, so TDs might be
 580  * processed as soon as they're queued.
 581  */
 582 static void td_submit_urb (
 583         struct ohci_hcd *ohci,
 584         struct urb      *urb
 585 ) {
 586         struct urb_priv *urb_priv = urb->hcpriv;
 587         dma_addr_t      data;
 588         int             data_len = urb->transfer_buffer_length;
 589         int             cnt = 0;
 590         u32             info = 0;
 591         int             is_out = usb_pipeout (urb->pipe);
 592         int             periodic = 0;
 593
 594         /* OHCI handles the bulk/interrupt data toggles itself.  We just
 595          * use the device toggle bits for resetting, and rely on the fact
 596          * that resetting toggle is meaningless if the endpoint is active.
 597          */
 598         if (!usb_gettoggle (urb->dev, usb_pipeendpoint (urb->pipe), is_out)) {
 599                 usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe),
 600                         is_out, 1);
 601                 urb_priv->ed->hwHeadP &= ~cpu_to_hc32 (ohci, ED_C);
 602         }
 603
 604         urb_priv->td_cnt = 0;
 605         list_add (&urb_priv->pending, &ohci->pending);
 606
 607         if (data_len)
 608                 data = urb->transfer_dma;
 609         else
 610                 data = 0;
 611
 612         /* NOTE:  TD_CC is set so we can tell which TDs the HC processed by
 613          * using TD_CC_GET, as well as by seeing them on the done list.
 614          * (CC = NotAccessed ... 0x0F, or 0x0E in PSWs for ISO.)
 615          */
 616         switch (urb_priv->ed->type) {
 617
 618         /* Bulk and interrupt are identical except for where in the schedule
 619          * their EDs live.
 620          */
 621         case PIPE_INTERRUPT:
 622                 /* ... and periodic urbs have extra accounting */
 623                 periodic = ohci_to_hcd(ohci)->self.bandwidth_int_reqs++ == 0
 624                         && ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0;
 625                 /* FALLTHROUGH */
 626         case PIPE_BULK:
 627                 info = is_out
 628                         ? TD_T_TOGGLE | TD_CC | TD_DP_OUT
 629                         : TD_T_TOGGLE | TD_CC | TD_DP_IN;
 630                 /* TDs _could_ transfer up to 8K each */
 631                 while (data_len > 4096) {
 632                         td_fill (ohci, info, data, 4096, urb, cnt);
 633                         data += 4096;
 634                         data_len -= 4096;
 635                         cnt++;
 636                 }
 637                 /* maybe avoid ED halt on final TD short read */
 638                 if (!(urb->transfer_flags & URB_SHORT_NOT_OK))
 639                         info |= TD_R;
 640                 td_fill (ohci, info, data, data_len, urb, cnt);
 641                 cnt++;
 642                 if ((urb->transfer_flags & URB_ZERO_PACKET)
 643                                 && cnt < urb_priv->length) {
 644                         td_fill (ohci, info, 0, 0, urb, cnt);
 645                         cnt++;
 646                 }
 647                 /* maybe kickstart bulk list */
 648                 if (urb_priv->ed->type == PIPE_BULK) {
 649                         wmb ();
 650                         ohci_writel (ohci, OHCI_BLF, &ohci->regs->cmdstatus);
 651                 }
 652                 break;
 653
 654         /* control manages DATA0/DATA1 toggle per-request; SETUP resets it,
 655          * any DATA phase works normally, and the STATUS ack is special.
 656          */
 657         case PIPE_CONTROL:
 658                 info = TD_CC | TD_DP_SETUP | TD_T_DATA0;
 659                 td_fill (ohci, info, urb->setup_dma, 8, urb, cnt++);
 660                 if (data_len > 0) {
 661                         info = TD_CC | TD_R | TD_T_DATA1;
 662                         info |= is_out ? TD_DP_OUT : TD_DP_IN;
 663                         /* NOTE:  mishandles transfers >8K, some >4K */
 664                         td_fill (ohci, info, data, data_len, urb, cnt++);
 665                 }
 666                 info = (is_out || data_len == 0)
 667                         ? TD_CC | TD_DP_IN | TD_T_DATA1
 668                         : TD_CC | TD_DP_OUT | TD_T_DATA1;
 669                 td_fill (ohci, info, data, 0, urb, cnt++);
 670                 /* maybe kickstart control list */
 671                 wmb ();
 672                 ohci_writel (ohci, OHCI_CLF, &ohci->regs->cmdstatus);
 673                 break;
 674
 675         /* ISO has no retransmit, so no toggle; and it uses special TDs.
 676          * Each TD could handle multiple consecutive frames (interval 1);
 677          * we could often reduce the number of TDs here.
 678          */
 679         case PIPE_ISOCHRONOUS:
 680                 for (cnt = 0; cnt < urb->number_of_packets; cnt++) {
 681                         int     frame = urb->start_frame;
 682
 683                         // FIXME scheduling should handle frame counter
 684                         // roll-around ... exotic case (and OHCI has
 685                         // a 2^16 iso range, vs other HCs max of 2^10)
 686                         frame += cnt * urb->interval;
 687                         frame &= 0xffff;
 688                         td_fill (ohci, TD_CC | TD_ISO | frame,
 689                                 data + urb->iso_frame_desc [cnt].offset,
 690                                 urb->iso_frame_desc [cnt].length, urb, cnt);
 691                 }
 692                 periodic = ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs++ == 0
 693                         && ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0;
 694                 break;
 695         }
 696
 697         /* start periodic dma if needed */
 698         if (periodic) {
 699                 wmb ();
 700                 ohci->hc_control |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
 701                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
 702         }
 703
 704         // ASSERT (urb_priv->length == cnt);
 705 }
 706
 707 /*-------------------------------------------------------------------------*
 708  * Done List handling functions
 709  *-------------------------------------------------------------------------*/
 710
 711 /* calculate transfer length/status and update the urb
 712  * PRECONDITION:  irqsafe (only for urb->status locking)
 713  */
 714 static void td_done (struct ohci_hcd *ohci, struct urb *urb, struct td *td)
 715 {
 716         u32     tdINFO = hc32_to_cpup (ohci, &td->hwINFO);
 717         int     cc = 0;
 718
 719         list_del (&td->td_list);
 720
 721         /* ISO ... drivers see per-TD length/status */
 722         if (tdINFO & TD_ISO) {
 723                 u16     tdPSW = ohci_hwPSW (ohci, td, 0);
 724                 int     dlen = 0;
 725
 726                 /* NOTE:  assumes FC in tdINFO == 0, and that
 727                  * only the first of 0..MAXPSW psws is used.
 728                  */
 729
 730                 cc = (tdPSW >> 12) & 0xF;
 731                 if (tdINFO & TD_CC)     /* hc didn't touch? */
 732                         return;
 733
 734                 if (usb_pipeout (urb->pipe))
 735                         dlen = urb->iso_frame_desc [td->index].length;
 736                 else {
 737                         /* short reads are always OK for ISO */
 738                         if (cc == TD_DATAUNDERRUN)
 739                                 cc = TD_CC_NOERROR;
 740                         dlen = tdPSW & 0x3ff;
 741                 }
 742                 urb->actual_length += dlen;
 743                 urb->iso_frame_desc [td->index].actual_length = dlen;
 744                 urb->iso_frame_desc [td->index].status = cc_to_error [cc];
 745
 746                 if (cc != TD_CC_NOERROR)
 747                         ohci_vdbg (ohci,
 748                                 "urb %p iso td %p (%d) len %d cc %d\n",
 749                                 urb, td, 1 + td->index, dlen, cc);
 750
 751         /* BULK, INT, CONTROL ... drivers see aggregate length/status,
 752          * except that "setup" bytes aren't counted and "short" transfers
 753          * might not be reported as errors.
 754          */
 755         } else {
 756                 int     type = usb_pipetype (urb->pipe);
 757                 u32     tdBE = hc32_to_cpup (ohci, &td->hwBE);
 758
 759                 cc = TD_CC_GET (tdINFO);
 760
 761                 /* update packet status if needed (short is normally ok) */
 762                 if (cc == TD_DATAUNDERRUN
 763                                 && !(urb->transfer_flags & URB_SHORT_NOT_OK))
 764                         cc = TD_CC_NOERROR;
 765                 if (cc != TD_CC_NOERROR && cc < 0x0E) {
 766                         spin_lock (&urb->lock);
 767                         if (urb->status == -EINPROGRESS)
 768                                 urb->status = cc_to_error [cc];
 769                         spin_unlock (&urb->lock);
 770                 }
 771
 772                 /* count all non-empty packets except control SETUP packet */
 773                 if ((type != PIPE_CONTROL || td->index != 0) && tdBE != 0) {
 774                         if (td->hwCBP == 0)
 775                                 urb->actual_length += tdBE - td->data_dma + 1;
 776                         else
 777                                 urb->actual_length +=
 778                                           hc32_to_cpup (ohci, &td->hwCBP)
 779                                         - td->data_dma;
 780                 }
 781
 782                 if (cc != TD_CC_NOERROR && cc < 0x0E)
 783                         ohci_vdbg (ohci,
 784                                 "urb %p td %p (%d) cc %d, len=%d/%d\n",
 785                                 urb, td, 1 + td->index, cc,
 786                                 urb->actual_length,
 787                                 urb->transfer_buffer_length);
 788         }
 789 }
 790
 791 /*-------------------------------------------------------------------------*/
 792
 793 static inline struct td *
 794 ed_halted (struct ohci_hcd *ohci, struct td *td, int cc, struct td *rev)
 795 {
 796         struct urb              *urb = td->urb;
 797         struct ed               *ed = td->ed;
 798         struct list_head        *tmp = td->td_list.next;
 799         __hc32                  toggle = ed->hwHeadP & cpu_to_hc32 (ohci, ED_C);
 800
 801         /* clear ed halt; this is the td that caused it, but keep it inactive
 802          * until its urb->complete() has a chance to clean up.
 803          */
 804         ed->hwINFO |= cpu_to_hc32 (ohci, ED_SKIP);
 805         wmb ();
 806         ed->hwHeadP &= ~cpu_to_hc32 (ohci, ED_H);
 807
 808         /* put any later tds from this urb onto the donelist, after 'td',
 809          * order won't matter here: no errors, and nothing was transferred.
 810          * also patch the ed so it looks as if those tds completed normally.
 811          */
 812         while (tmp != &ed->td_list) {
 813                 struct td       *next;
 814                 __hc32          info;
 815
 816                 next = list_entry (tmp, struct td, td_list);
 817                 tmp = next->td_list.next;
 818
 819                 if (next->urb != urb)
 820                         break;
 821
 822                 /* NOTE: if multi-td control DATA segments get supported,
 823                  * this urb had one of them, this td wasn't the last td
 824                  * in that segment (TD_R clear), this ed halted because
 825                  * of a short read, _and_ URB_SHORT_NOT_OK is clear ...
 826                  * then we need to leave the control STATUS packet queued
 827                  * and clear ED_SKIP.
 828                  */
 829                 info = next->hwINFO;
 830                 info |= cpu_to_hc32 (ohci, TD_DONE);
 831                 info &= ~cpu_to_hc32 (ohci, TD_CC);
 832                 next->hwINFO = info;
 833
 834                 next->next_dl_td = rev;
 835                 rev = next;
 836
 837                 ed->hwHeadP = next->hwNextTD | toggle;
 838         }
 839
 840         /* help for troubleshooting:  report anything that
 841          * looks odd ... that doesn't include protocol stalls
 842          * (or maybe some other things)
 843          */
 844         switch (cc) {
 845         case TD_DATAUNDERRUN:
 846                 if ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0)
 847                         break;
 848                 /* fallthrough */
 849         case TD_CC_STALL:
 850                 if (usb_pipecontrol (urb->pipe))
 851                         break;
 852                 /* fallthrough */
 853         default:
 854                 ohci_dbg (ohci,
 855                         "urb %p path %s ep%d%s %08x cc %d --> status %d\n",
 856                         urb, urb->dev->devpath,
 857                         usb_pipeendpoint (urb->pipe),
 858                         usb_pipein (urb->pipe) ? "in" : "out",
 859                         hc32_to_cpu (ohci, td->hwINFO),
 860                         cc, cc_to_error [cc]);
 861         }
 862
 863         return rev;
 864 }
 865
 866 /* replies to the request have to be on a FIFO basis so
 867  * we unreverse the hc-reversed done-list
 868  */
 869 static struct td *dl_reverse_done_list (struct ohci_hcd *ohci)
 870 {
 871         u32             td_dma;
 872         struct td       *td_rev = NULL;
 873         struct td       *td = NULL;
 874
 875         td_dma = hc32_to_cpup (ohci, &ohci->hcca->done_head);
 876         ohci->hcca->done_head = 0;
 877         wmb();
 878
 879         /* get TD from hc's singly linked list, and
 880          * prepend to ours.  ed->td_list changes later.
 881          */
 882         while (td_dma) {
 883                 int             cc;
 884
 885                 td = dma_to_td (ohci, td_dma);
 886                 if (!td) {
 887                         ohci_err (ohci, "bad entry %8x\n", td_dma);
 888                         break;
 889                 }
 890
 891                 td->hwINFO |= cpu_to_hc32 (ohci, TD_DONE);
 892                 cc = TD_CC_GET (hc32_to_cpup (ohci, &td->hwINFO));
 893
 894                 /* Non-iso endpoints can halt on error; un-halt,
 895                  * and dequeue any other TDs from this urb.
 896                  * No other TD could have caused the halt.
 897                  */
 898                 if (cc != TD_CC_NOERROR
 899                                 && (td->ed->hwHeadP & cpu_to_hc32 (ohci, ED_H)))
 900                         td_rev = ed_halted (ohci, td, cc, td_rev);
 901
 902                 td->next_dl_td = td_rev;
 903                 td_rev = td;
 904                 td_dma = hc32_to_cpup (ohci, &td->hwNextTD);
 905         }
 906         return td_rev;
 907 }
 908
 909 /*-------------------------------------------------------------------------*/
 910
 911 /* there are some urbs/eds to unlink; called in_irq(), with HCD locked */
 912 static void
 913 finish_unlinks (struct ohci_hcd *ohci, u16 tick)
 914 {
 915         struct ed       *ed, **last;
 916
 917 rescan_all:
 918         for (last = &ohci->ed_rm_list, ed = *last; ed != NULL; ed = *last) {
 919                 struct list_head        *entry, *tmp;
 920                 int                     completed, modified;
 921                 __hc32                  *prev;
 922
 923                 /* only take off EDs that the HC isn't using, accounting for
 924                  * frame counter wraps and EDs with partially retired TDs
 925                  */
 926                 if (likely (HC_IS_RUNNING(ohci_to_hcd(ohci)->state))) {
 927                         if (tick_before (tick, ed->tick)) {
 928 skip_ed:
 929                                 last = &ed->ed_next;
 930                                 continue;
 931                         }
 932
 933                         if (!list_empty (&ed->td_list)) {
 934                                 struct td       *td;
 935                                 u32             head;
 936
 937                                 td = list_entry (ed->td_list.next, struct td,
 938                                                         td_list);
 939                                 head = hc32_to_cpu (ohci, ed->hwHeadP) &
 940                                                                 TD_MASK;
 941
 942                                 /* INTR_WDH may need to clean up first */
 943                                 if (td->td_dma != head)
 944                                         goto skip_ed;
 945                         }
 946                 }
 947
 948                 /* reentrancy:  if we drop the schedule lock, someone might
 949                  * have modified this list.  normally it's just prepending
 950                  * entries (which we'd ignore), but paranoia won't hurt.
 951                  */
 952                 *last = ed->ed_next;
 953                 ed->ed_next = NULL;
 954                 modified = 0;
 955
 956                 /* unlink urbs as requested, but rescan the list after
 957                  * we call a completion since it might have unlinked
 958                  * another (earlier) urb
 959                  *
 960                  * When we get here, the HC doesn't see this ed.  But it
 961                  * must not be rescheduled until all completed URBs have
 962                  * been given back to the driver.
 963                  */
 964 rescan_this:
 965                 completed = 0;
 966                 prev = &ed->hwHeadP;
 967                 list_for_each_safe (entry, tmp, &ed->td_list) {
 968                         struct td       *td;
 969                         struct urb      *urb;
 970                         urb_priv_t      *urb_priv;
 971                         __hc32          savebits;
 972
 973                         td = list_entry (entry, struct td, td_list);
 974                         urb = td->urb;
 975                         urb_priv = td->urb->hcpriv;
 976
 977                         if (urb->status == -EINPROGRESS) {
 978                                 prev = &td->hwNextTD;
 979                                 continue;
 980                         }
 981
 982                         /* patch pointer hc uses */
 983                         savebits = *prev & ~cpu_to_hc32 (ohci, TD_MASK);
 984                         *prev = td->hwNextTD | savebits;
 985
 986                         /* HC may have partly processed this TD */
 987                         td_done (ohci, urb, td);
 988                         urb_priv->td_cnt++;
 989
 990                         /* if URB is done, clean up */
 991                         if (urb_priv->td_cnt == urb_priv->length) {
 992                                 modified = completed = 1;
 993                                 finish_urb (ohci, urb);
 994                         }
 995                 }
 996                 if (completed && !list_empty (&ed->td_list))
 997                         goto rescan_this;
 998
 999                 /* ED's now officially unlinked, hc doesn't see */
1000                 ed->state = ED_IDLE;
1001                 ed->hwHeadP &= ~cpu_to_hc32(ohci, ED_H);
1002                 ed->hwNextED = 0;
1003                 wmb ();
1004                 ed->hwINFO &= ~cpu_to_hc32 (ohci, ED_SKIP | ED_DEQUEUE);
1005
1006                 /* but if there's work queued, reschedule */
1007                 if (!list_empty (&ed->td_list)) {
1008                         if (HC_IS_RUNNING(ohci_to_hcd(ohci)->state))
1009                                 ed_schedule (ohci, ed);
1010                 }
1011
1012                 if (modified)
1013                         goto rescan_all;
1014         }
1015
1016         /* maybe reenable control and bulk lists */
1017         if (HC_IS_RUNNING(ohci_to_hcd(ohci)->state)
1018                         && ohci_to_hcd(ohci)->state != HC_STATE_QUIESCING
1019                         && !ohci->ed_rm_list) {
1020                 u32     command = 0, control = 0;
1021
1022                 if (ohci->ed_controltail) {
1023                         command |= OHCI_CLF;
1024                         if (ohci->flags & OHCI_QUIRK_ZFMICRO)
1025                                 mdelay(1);
1026                         if (!(ohci->hc_control & OHCI_CTRL_CLE)) {
1027                                 control |= OHCI_CTRL_CLE;
1028                                 ohci_writel (ohci, 0,
1029                                         &ohci->regs->ed_controlcurrent);
1030                         }
1031                 }
1032                 if (ohci->ed_bulktail) {
1033                         command |= OHCI_BLF;
1034                         if (ohci->flags & OHCI_QUIRK_ZFMICRO)
1035                                 mdelay(1);
1036                         if (!(ohci->hc_control & OHCI_CTRL_BLE)) {
1037                                 control |= OHCI_CTRL_BLE;
1038                                 ohci_writel (ohci, 0,
1039                                         &ohci->regs->ed_bulkcurrent);
1040                         }
1041                 }
1042
1043                 /* CLE/BLE to enable, CLF/BLF to (maybe) kickstart */
1044                 if (control) {
1045                         ohci->hc_control |= control;
1046                         if (ohci->flags & OHCI_QUIRK_ZFMICRO)
1047                                 mdelay(1);
1048                         ohci_writel (ohci, ohci->hc_control,
1049                                         &ohci->regs->control);
1050                 }
1051                 if (command) {
1052                         if (ohci->flags & OHCI_QUIRK_ZFMICRO)
1053                                 mdelay(1);
1054                         ohci_writel (ohci, command, &ohci->regs->cmdstatus);
1055                 }
1056         }
1057 }
1058
1059
1060
1061 /*-------------------------------------------------------------------------*/
1062
1063 /*
1064  * Process normal completions (error or success) and clean the schedules.
1065  *
1066  * This is the main path for handing urbs back to drivers.  The only other
1067  * path is finish_unlinks(), which unlinks URBs using ed_rm_list, instead of
1068  * scanning the (re-reversed) donelist as this does.
1069  */
1070 static void
1071 dl_done_list (struct ohci_hcd *ohci)
1072 {
1073         struct td       *td = dl_reverse_done_list (ohci);
1074
1075         while (td) {
1076                 struct td       *td_next = td->next_dl_td;
1077                 struct urb      *urb = td->urb;
1078                 urb_priv_t      *urb_priv = urb->hcpriv;
1079                 struct ed       *ed = td->ed;
1080
1081                 /* update URB's length and status from TD */
1082                 td_done (ohci, urb, td);
1083                 urb_priv->td_cnt++;
1084
1085                 /* If all this urb's TDs are done, call complete() */
1086                 if (urb_priv->td_cnt == urb_priv->length)
1087                         finish_urb (ohci, urb);
1088
1089                 /* clean schedule:  unlink EDs that are no longer busy */
1090                 if (list_empty (&ed->td_list)) {
1091                         if (ed->state == ED_OPER)
1092                                 start_ed_unlink (ohci, ed);
1093
1094                 /* ... reenabling halted EDs only after fault cleanup */
1095                 } else if ((ed->hwINFO & cpu_to_hc32 (ohci,
1096                                                 ED_SKIP | ED_DEQUEUE))
1097                                         == cpu_to_hc32 (ohci, ED_SKIP)) {
1098                         td = list_entry (ed->td_list.next, struct td, td_list);
1099                         if (!(td->hwINFO & cpu_to_hc32 (ohci, TD_DONE))) {
1100                                 ed->hwINFO &= ~cpu_to_hc32 (ohci, ED_SKIP);
1101                                 /* ... hc may need waking-up */
1102                                 switch (ed->type) {
1103                                 case PIPE_CONTROL:
1104                                         ohci_writel (ohci, OHCI_CLF,
1105                                                 &ohci->regs->cmdstatus);
1106                                         break;
1107                                 case PIPE_BULK:
1108                                         ohci_writel (ohci, OHCI_BLF,
1109                                                 &ohci->regs->cmdstatus);
1110                                         break;
1111                                 }
1112                         }
1113                 }
1114
1115                 td = td_next;
1116         }
1117 }