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

   1 /*
   2  * Universal Host Controller Interface driver for USB.
   3  *
   4  * Maintainer: Alan Stern <stern@rowland.harvard.edu>
   5  *
   6  * (C) Copyright 1999 Linus Torvalds
   7  * (C) Copyright 1999-2002 Johannes Erdfelt, johannes@erdfelt.com
   8  * (C) Copyright 1999 Randy Dunlap
   9  * (C) Copyright 1999 Georg Acher, acher@in.tum.de
  10  * (C) Copyright 1999 Deti Fliegl, deti@fliegl.de
  11  * (C) Copyright 1999 Thomas Sailer, sailer@ife.ee.ethz.ch
  12  * (C) Copyright 1999 Roman Weissgaerber, weissg@vienna.at
  13  * (C) Copyright 2000 Yggdrasil Computing, Inc. (port of new PCI interface
  14  *               support from usb-ohci.c by Adam Richter, adam@yggdrasil.com).
  15  * (C) Copyright 1999 Gregory P. Smith (from usb-ohci.c)
  16  * (C) Copyright 2004-2007 Alan Stern, stern@rowland.harvard.edu
  17  */
  18
  19
  20 /*
  21  * Technically, updating td->status here is a race, but it's not really a
  22  * problem. The worst that can happen is that we set the IOC bit again
  23  * generating a spurious interrupt. We could fix this by creating another
  24  * QH and leaving the IOC bit always set, but then we would have to play
  25  * games with the FSBR code to make sure we get the correct order in all
  26  * the cases. I don't think it's worth the effort
  27  */
  28 static void uhci_set_next_interrupt(struct uhci_hcd *uhci)
  29 {
  30         if (uhci->is_stopped)
  31                 mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies);
  32         uhci->term_td->status |= cpu_to_le32(TD_CTRL_IOC);
  33 }
  34
  35 static inline void uhci_clear_next_interrupt(struct uhci_hcd *uhci)
  36 {
  37         uhci->term_td->status &= ~cpu_to_le32(TD_CTRL_IOC);
  38 }
  39
  40
  41 /*
  42  * Full-Speed Bandwidth Reclamation (FSBR).
  43  * We turn on FSBR whenever a queue that wants it is advancing,
  44  * and leave it on for a short time thereafter.
  45  */
  46 static void uhci_fsbr_on(struct uhci_hcd *uhci)
  47 {
  48         struct uhci_qh *fsbr_qh, *lqh, *tqh;
  49
  50         uhci->fsbr_is_on = 1;
  51         lqh = list_entry(uhci->skel_async_qh->node.prev,
  52                         struct uhci_qh, node);
  53
  54         /* Find the first FSBR QH.  Linear search through the list is
  55          * acceptable because normally FSBR gets turned on as soon as
  56          * one QH needs it. */
  57         fsbr_qh = NULL;
  58         list_for_each_entry_reverse(tqh, &uhci->skel_async_qh->node, node) {
  59                 if (tqh->skel < SKEL_FSBR)
  60                         break;
  61                 fsbr_qh = tqh;
  62         }
  63
  64         /* No FSBR QH means we must insert the terminating skeleton QH */
  65         if (!fsbr_qh) {
  66                 uhci->skel_term_qh->link = LINK_TO_QH(uhci->skel_term_qh);
  67                 wmb();
  68                 lqh->link = uhci->skel_term_qh->link;
  69
  70         /* Otherwise loop the last QH to the first FSBR QH */
  71         } else
  72                 lqh->link = LINK_TO_QH(fsbr_qh);
  73 }
  74
  75 static void uhci_fsbr_off(struct uhci_hcd *uhci)
  76 {
  77         struct uhci_qh *lqh;
  78
  79         uhci->fsbr_is_on = 0;
  80         lqh = list_entry(uhci->skel_async_qh->node.prev,
  81                         struct uhci_qh, node);
  82
  83         /* End the async list normally and unlink the terminating QH */
  84         lqh->link = uhci->skel_term_qh->link = UHCI_PTR_TERM;
  85 }
  86
  87 static void uhci_add_fsbr(struct uhci_hcd *uhci, struct urb *urb)
  88 {
  89         struct urb_priv *urbp = urb->hcpriv;
  90
  91         if (!(urb->transfer_flags & URB_NO_FSBR))
  92                 urbp->fsbr = 1;
  93 }
  94
  95 static void uhci_urbp_wants_fsbr(struct uhci_hcd *uhci, struct urb_priv *urbp)
  96 {
  97         if (urbp->fsbr) {
  98                 uhci->fsbr_is_wanted = 1;
  99                 if (!uhci->fsbr_is_on)
 100                         uhci_fsbr_on(uhci);
 101                 else if (uhci->fsbr_expiring) {
 102                         uhci->fsbr_expiring = 0;
 103                         del_timer(&uhci->fsbr_timer);
 104                 }
 105         }
 106 }
 107
 108 static void uhci_fsbr_timeout(unsigned long _uhci)
 109 {
 110         struct uhci_hcd *uhci = (struct uhci_hcd *) _uhci;
 111         unsigned long flags;
 112
 113         spin_lock_irqsave(&uhci->lock, flags);
 114         if (uhci->fsbr_expiring) {
 115                 uhci->fsbr_expiring = 0;
 116                 uhci_fsbr_off(uhci);
 117         }
 118         spin_unlock_irqrestore(&uhci->lock, flags);
 119 }
 120
 121
 122 static struct uhci_td *uhci_alloc_td(struct uhci_hcd *uhci)
 123 {
 124         dma_addr_t dma_handle;
 125         struct uhci_td *td;
 126
 127         td = dma_pool_alloc(uhci->td_pool, GFP_ATOMIC, &dma_handle);
 128         if (!td)
 129                 return NULL;
 130
 131         td->dma_handle = dma_handle;
 132         td->frame = -1;
 133
 134         INIT_LIST_HEAD(&td->list);
 135         INIT_LIST_HEAD(&td->fl_list);
 136
 137         return td;
 138 }
 139
 140 static void uhci_free_td(struct uhci_hcd *uhci, struct uhci_td *td)
 141 {
 142         if (!list_empty(&td->list))
 143                 dev_warn(uhci_dev(uhci), "td %p still in list!\n", td);
 144         if (!list_empty(&td->fl_list))
 145                 dev_warn(uhci_dev(uhci), "td %p still in fl_list!\n", td);
 146
 147         dma_pool_free(uhci->td_pool, td, td->dma_handle);
 148 }
 149
 150 static inline void uhci_fill_td(struct uhci_td *td, u32 status,
 151                 u32 token, u32 buffer)
 152 {
 153         td->status = cpu_to_le32(status);
 154         td->token = cpu_to_le32(token);
 155         td->buffer = cpu_to_le32(buffer);
 156 }
 157
 158 static void uhci_add_td_to_urbp(struct uhci_td *td, struct urb_priv *urbp)
 159 {
 160         list_add_tail(&td->list, &urbp->td_list);
 161 }
 162
 163 static void uhci_remove_td_from_urbp(struct uhci_td *td)
 164 {
 165         list_del_init(&td->list);
 166 }
 167
 168 /*
 169  * We insert Isochronous URBs directly into the frame list at the beginning
 170  */
 171 static inline void uhci_insert_td_in_frame_list(struct uhci_hcd *uhci,
 172                 struct uhci_td *td, unsigned framenum)
 173 {
 174         framenum &= (UHCI_NUMFRAMES - 1);
 175
 176         td->frame = framenum;
 177
 178         /* Is there a TD already mapped there? */
 179         if (uhci->frame_cpu[framenum]) {
 180                 struct uhci_td *ftd, *ltd;
 181
 182                 ftd = uhci->frame_cpu[framenum];
 183                 ltd = list_entry(ftd->fl_list.prev, struct uhci_td, fl_list);
 184
 185                 list_add_tail(&td->fl_list, &ftd->fl_list);
 186
 187                 td->link = ltd->link;
 188                 wmb();
 189                 ltd->link = LINK_TO_TD(td);
 190         } else {
 191                 td->link = uhci->frame[framenum];
 192                 wmb();
 193                 uhci->frame[framenum] = LINK_TO_TD(td);
 194                 uhci->frame_cpu[framenum] = td;
 195         }
 196 }
 197
 198 static inline void uhci_remove_td_from_frame_list(struct uhci_hcd *uhci,
 199                 struct uhci_td *td)
 200 {
 201         /* If it's not inserted, don't remove it */
 202         if (td->frame == -1) {
 203                 WARN_ON(!list_empty(&td->fl_list));
 204                 return;
 205         }
 206
 207         if (uhci->frame_cpu[td->frame] == td) {
 208                 if (list_empty(&td->fl_list)) {
 209                         uhci->frame[td->frame] = td->link;
 210                         uhci->frame_cpu[td->frame] = NULL;
 211                 } else {
 212                         struct uhci_td *ntd;
 213
 214                         ntd = list_entry(td->fl_list.next, struct uhci_td, fl_list);
 215                         uhci->frame[td->frame] = LINK_TO_TD(ntd);
 216                         uhci->frame_cpu[td->frame] = ntd;
 217                 }
 218         } else {
 219                 struct uhci_td *ptd;
 220
 221                 ptd = list_entry(td->fl_list.prev, struct uhci_td, fl_list);
 222                 ptd->link = td->link;
 223         }
 224
 225         list_del_init(&td->fl_list);
 226         td->frame = -1;
 227 }
 228
 229 static inline void uhci_remove_tds_from_frame(struct uhci_hcd *uhci,
 230                 unsigned int framenum)
 231 {
 232         struct uhci_td *ftd, *ltd;
 233
 234         framenum &= (UHCI_NUMFRAMES - 1);
 235
 236         ftd = uhci->frame_cpu[framenum];
 237         if (ftd) {
 238                 ltd = list_entry(ftd->fl_list.prev, struct uhci_td, fl_list);
 239                 uhci->frame[framenum] = ltd->link;
 240                 uhci->frame_cpu[framenum] = NULL;
 241
 242                 while (!list_empty(&ftd->fl_list))
 243                         list_del_init(ftd->fl_list.prev);
 244         }
 245 }
 246
 247 /*
 248  * Remove all the TDs for an Isochronous URB from the frame list
 249  */
 250 static void uhci_unlink_isochronous_tds(struct uhci_hcd *uhci, struct urb *urb)
 251 {
 252         struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
 253         struct uhci_td *td;
 254
 255         list_for_each_entry(td, &urbp->td_list, list)
 256                 uhci_remove_td_from_frame_list(uhci, td);
 257 }
 258
 259 static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci,
 260                 struct usb_device *udev, struct usb_host_endpoint *hep)
 261 {
 262         dma_addr_t dma_handle;
 263         struct uhci_qh *qh;
 264
 265         qh = dma_pool_alloc(uhci->qh_pool, GFP_ATOMIC, &dma_handle);
 266         if (!qh)
 267                 return NULL;
 268
 269         memset(qh, 0, sizeof(*qh));
 270         qh->dma_handle = dma_handle;
 271
 272         qh->element = UHCI_PTR_TERM;
 273         qh->link = UHCI_PTR_TERM;
 274
 275         INIT_LIST_HEAD(&qh->queue);
 276         INIT_LIST_HEAD(&qh->node);
 277
 278         if (udev) {             /* Normal QH */
 279                 qh->type = hep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
 280                 if (qh->type != USB_ENDPOINT_XFER_ISOC) {
 281                         qh->dummy_td = uhci_alloc_td(uhci);
 282                         if (!qh->dummy_td) {
 283                                 dma_pool_free(uhci->qh_pool, qh, dma_handle);
 284                                 return NULL;
 285                         }
 286                 }
 287                 qh->state = QH_STATE_IDLE;
 288                 qh->hep = hep;
 289                 qh->udev = udev;
 290                 hep->hcpriv = qh;
 291
 292                 if (qh->type == USB_ENDPOINT_XFER_INT ||
 293                                 qh->type == USB_ENDPOINT_XFER_ISOC)
 294                         qh->load = usb_calc_bus_time(udev->speed,
 295                                         usb_endpoint_dir_in(&hep->desc),
 296                                         qh->type == USB_ENDPOINT_XFER_ISOC,
 297                                         le16_to_cpu(hep->desc.wMaxPacketSize))
 298                                 / 1000 + 1;
 299
 300         } else {                /* Skeleton QH */
 301                 qh->state = QH_STATE_ACTIVE;
 302                 qh->type = -1;
 303         }
 304         return qh;
 305 }
 306
 307 static void uhci_free_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 308 {
 309         WARN_ON(qh->state != QH_STATE_IDLE && qh->udev);
 310         if (!list_empty(&qh->queue))
 311                 dev_warn(uhci_dev(uhci), "qh %p list not empty!\n", qh);
 312
 313         list_del(&qh->node);
 314         if (qh->udev) {
 315                 qh->hep->hcpriv = NULL;
 316                 if (qh->dummy_td)
 317                         uhci_free_td(uhci, qh->dummy_td);
 318         }
 319         dma_pool_free(uhci->qh_pool, qh, qh->dma_handle);
 320 }
 321
 322 /*
 323  * When a queue is stopped and a dequeued URB is given back, adjust
 324  * the previous TD link (if the URB isn't first on the queue) or
 325  * save its toggle value (if it is first and is currently executing).
 326  *
 327  * Returns 0 if the URB should not yet be given back, 1 otherwise.
 328  */
 329 static int uhci_cleanup_queue(struct uhci_hcd *uhci, struct uhci_qh *qh,
 330                 struct urb *urb)
 331 {
 332         struct urb_priv *urbp = urb->hcpriv;
 333         struct uhci_td *td;
 334         int ret = 1;
 335
 336         /* Isochronous pipes don't use toggles and their TD link pointers
 337          * get adjusted during uhci_urb_dequeue().  But since their queues
 338          * cannot truly be stopped, we have to watch out for dequeues
 339          * occurring after the nominal unlink frame. */
 340         if (qh->type == USB_ENDPOINT_XFER_ISOC) {
 341                 ret = (uhci->frame_number + uhci->is_stopped !=
 342                                 qh->unlink_frame);
 343                 goto done;
 344         }
 345
 346         /* If the URB isn't first on its queue, adjust the link pointer
 347          * of the last TD in the previous URB.  The toggle doesn't need
 348          * to be saved since this URB can't be executing yet. */
 349         if (qh->queue.next != &urbp->node) {
 350                 struct urb_priv *purbp;
 351                 struct uhci_td *ptd;
 352
 353                 purbp = list_entry(urbp->node.prev, struct urb_priv, node);
 354                 WARN_ON(list_empty(&purbp->td_list));
 355                 ptd = list_entry(purbp->td_list.prev, struct uhci_td,
 356                                 list);
 357                 td = list_entry(urbp->td_list.prev, struct uhci_td,
 358                                 list);
 359                 ptd->link = td->link;
 360                 goto done;
 361         }
 362
 363         /* If the QH element pointer is UHCI_PTR_TERM then then currently
 364          * executing URB has already been unlinked, so this one isn't it. */
 365         if (qh_element(qh) == UHCI_PTR_TERM)
 366                 goto done;
 367         qh->element = UHCI_PTR_TERM;
 368
 369         /* Control pipes don't have to worry about toggles */
 370         if (qh->type == USB_ENDPOINT_XFER_CONTROL)
 371                 goto done;
 372
 373         /* Save the next toggle value */
 374         WARN_ON(list_empty(&urbp->td_list));
 375         td = list_entry(urbp->td_list.next, struct uhci_td, list);
 376         qh->needs_fixup = 1;
 377         qh->initial_toggle = uhci_toggle(td_token(td));
 378
 379 done:
 380         return ret;
 381 }
 382
 383 /*
 384  * Fix up the data toggles for URBs in a queue, when one of them
 385  * terminates early (short transfer, error, or dequeued).
 386  */
 387 static void uhci_fixup_toggles(struct uhci_qh *qh, int skip_first)
 388 {
 389         struct urb_priv *urbp = NULL;
 390         struct uhci_td *td;
 391         unsigned int toggle = qh->initial_toggle;
 392         unsigned int pipe;
 393
 394         /* Fixups for a short transfer start with the second URB in the
 395          * queue (the short URB is the first). */
 396         if (skip_first)
 397                 urbp = list_entry(qh->queue.next, struct urb_priv, node);
 398
 399         /* When starting with the first URB, if the QH element pointer is
 400          * still valid then we know the URB's toggles are okay. */
 401         else if (qh_element(qh) != UHCI_PTR_TERM)
 402                 toggle = 2;
 403
 404         /* Fix up the toggle for the URBs in the queue.  Normally this
 405          * loop won't run more than once: When an error or short transfer
 406          * occurs, the queue usually gets emptied. */
 407         urbp = list_prepare_entry(urbp, &qh->queue, node);
 408         list_for_each_entry_continue(urbp, &qh->queue, node) {
 409
 410                 /* If the first TD has the right toggle value, we don't
 411                  * need to change any toggles in this URB */
 412                 td = list_entry(urbp->td_list.next, struct uhci_td, list);
 413                 if (toggle > 1 || uhci_toggle(td_token(td)) == toggle) {
 414                         td = list_entry(urbp->td_list.prev, struct uhci_td,
 415                                         list);
 416                         toggle = uhci_toggle(td_token(td)) ^ 1;
 417
 418                 /* Otherwise all the toggles in the URB have to be switched */
 419                 } else {
 420                         list_for_each_entry(td, &urbp->td_list, list) {
 421                                 td->token ^= __constant_cpu_to_le32(
 422                                                         TD_TOKEN_TOGGLE);
 423                                 toggle ^= 1;
 424                         }
 425                 }
 426         }
 427
 428         wmb();
 429         pipe = list_entry(qh->queue.next, struct urb_priv, node)->urb->pipe;
 430         usb_settoggle(qh->udev, usb_pipeendpoint(pipe),
 431                         usb_pipeout(pipe), toggle);
 432         qh->needs_fixup = 0;
 433 }
 434
 435 /*
 436  * Link an Isochronous QH into its skeleton's list
 437  */
 438 static inline void link_iso(struct uhci_hcd *uhci, struct uhci_qh *qh)
 439 {
 440         list_add_tail(&qh->node, &uhci->skel_iso_qh->node);
 441
 442         /* Isochronous QHs aren't linked by the hardware */
 443 }
 444
 445 /*
 446  * Link a high-period interrupt QH into the schedule at the end of its
 447  * skeleton's list
 448  */
 449 static void link_interrupt(struct uhci_hcd *uhci, struct uhci_qh *qh)
 450 {
 451         struct uhci_qh *pqh;
 452
 453         list_add_tail(&qh->node, &uhci->skelqh[qh->skel]->node);
 454
 455         pqh = list_entry(qh->node.prev, struct uhci_qh, node);
 456         qh->link = pqh->link;
 457         wmb();
 458         pqh->link = LINK_TO_QH(qh);
 459 }
 460
 461 /*
 462  * Link a period-1 interrupt or async QH into the schedule at the
 463  * correct spot in the async skeleton's list, and update the FSBR link
 464  */
 465 static void link_async(struct uhci_hcd *uhci, struct uhci_qh *qh)
 466 {
 467         struct uhci_qh *pqh, *lqh;
 468         __le32 link_to_new_qh;
 469         __le32 *extra_link = &link_to_new_qh;
 470
 471         /* Find the predecessor QH for our new one and insert it in the list.
 472          * The list of QHs is expected to be short, so linear search won't
 473          * take too long. */
 474         list_for_each_entry_reverse(pqh, &uhci->skel_async_qh->node, node) {
 475                 if (pqh->skel <= qh->skel)
 476                         break;
 477         }
 478         list_add(&qh->node, &pqh->node);
 479         qh->link = pqh->link;
 480
 481         link_to_new_qh = LINK_TO_QH(qh);
 482
 483         /* If this is now the first FSBR QH, take special action */
 484         if (uhci->fsbr_is_on && pqh->skel < SKEL_FSBR &&
 485                         qh->skel >= SKEL_FSBR) {
 486                 lqh = list_entry(uhci->skel_async_qh->node.prev,
 487                                 struct uhci_qh, node);
 488
 489                 /* If the new QH is also the last one, we must unlink
 490                  * the terminating skeleton QH and make the new QH point
 491                  * back to itself. */
 492                 if (qh == lqh) {
 493                         qh->link = link_to_new_qh;
 494                         extra_link = &uhci->skel_term_qh->link;
 495
 496                 /* Otherwise the last QH must point to the new QH */
 497                 } else
 498                         extra_link = &lqh->link;
 499         }
 500
 501         /* Link it into the schedule */
 502         wmb();
 503         *extra_link = pqh->link = link_to_new_qh;
 504 }
 505
 506 /*
 507  * Put a QH on the schedule in both hardware and software
 508  */
 509 static void uhci_activate_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 510 {
 511         WARN_ON(list_empty(&qh->queue));
 512
 513         /* Set the element pointer if it isn't set already.
 514          * This isn't needed for Isochronous queues, but it doesn't hurt. */
 515         if (qh_element(qh) == UHCI_PTR_TERM) {
 516                 struct urb_priv *urbp = list_entry(qh->queue.next,
 517                                 struct urb_priv, node);
 518                 struct uhci_td *td = list_entry(urbp->td_list.next,
 519                                 struct uhci_td, list);
 520
 521                 qh->element = LINK_TO_TD(td);
 522         }
 523
 524         /* Treat the queue as if it has just advanced */
 525         qh->wait_expired = 0;
 526         qh->advance_jiffies = jiffies;
 527
 528         if (qh->state == QH_STATE_ACTIVE)
 529                 return;
 530         qh->state = QH_STATE_ACTIVE;
 531
 532         /* Move the QH from its old list to the correct spot in the appropriate
 533          * skeleton's list */
 534         if (qh == uhci->next_qh)
 535                 uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
 536                                 node);
 537         list_del(&qh->node);
 538
 539         if (qh->skel == SKEL_ISO)
 540                 link_iso(uhci, qh);
 541         else if (qh->skel < SKEL_ASYNC)
 542                 link_interrupt(uhci, qh);
 543         else
 544                 link_async(uhci, qh);
 545 }
 546
 547 /*
 548  * Unlink a high-period interrupt QH from the schedule
 549  */
 550 static void unlink_interrupt(struct uhci_hcd *uhci, struct uhci_qh *qh)
 551 {
 552         struct uhci_qh *pqh;
 553
 554         pqh = list_entry(qh->node.prev, struct uhci_qh, node);
 555         pqh->link = qh->link;
 556         mb();
 557 }
 558
 559 /*
 560  * Unlink a period-1 interrupt or async QH from the schedule
 561  */
 562 static void unlink_async(struct uhci_hcd *uhci, struct uhci_qh *qh)
 563 {
 564         struct uhci_qh *pqh, *lqh;
 565         __le32 link_to_next_qh = qh->link;
 566
 567         pqh = list_entry(qh->node.prev, struct uhci_qh, node);
 568
 569         /* If this is the first FSBQ QH, take special action */
 570         if (uhci->fsbr_is_on && pqh->skel < SKEL_FSBR &&
 571                         qh->skel >= SKEL_FSBR) {
 572                 lqh = list_entry(uhci->skel_async_qh->node.prev,
 573                                 struct uhci_qh, node);
 574
 575                 /* If this QH is also the last one, we must link in
 576                  * the terminating skeleton QH. */
 577                 if (qh == lqh) {
 578                         link_to_next_qh = LINK_TO_QH(uhci->skel_term_qh);
 579                         uhci->skel_term_qh->link = link_to_next_qh;
 580                         wmb();
 581                         qh->link = link_to_next_qh;
 582
 583                 /* Otherwise the last QH must point to the new first FSBR QH */
 584                 } else
 585                         lqh->link = link_to_next_qh;
 586         }
 587
 588         pqh->link = link_to_next_qh;
 589         mb();
 590 }
 591
 592 /*
 593  * Take a QH off the hardware schedule
 594  */
 595 static void uhci_unlink_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 596 {
 597         if (qh->state == QH_STATE_UNLINKING)
 598                 return;
 599         WARN_ON(qh->state != QH_STATE_ACTIVE || !qh->udev);
 600         qh->state = QH_STATE_UNLINKING;
 601
 602         /* Unlink the QH from the schedule and record when we did it */
 603         if (qh->skel == SKEL_ISO)
 604                 ;
 605         else if (qh->skel < SKEL_ASYNC)
 606                 unlink_interrupt(uhci, qh);
 607         else
 608                 unlink_async(uhci, qh);
 609
 610         uhci_get_current_frame_number(uhci);
 611         qh->unlink_frame = uhci->frame_number;
 612
 613         /* Force an interrupt so we know when the QH is fully unlinked */
 614         if (list_empty(&uhci->skel_unlink_qh->node))
 615                 uhci_set_next_interrupt(uhci);
 616
 617         /* Move the QH from its old list to the end of the unlinking list */
 618         if (qh == uhci->next_qh)
 619                 uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
 620                                 node);
 621         list_move_tail(&qh->node, &uhci->skel_unlink_qh->node);
 622 }
 623
 624 /*
 625  * When we and the controller are through with a QH, it becomes IDLE.
 626  * This happens when a QH has been off the schedule (on the unlinking
 627  * list) for more than one frame, or when an error occurs while adding
 628  * the first URB onto a new QH.
 629  */
 630 static void uhci_make_qh_idle(struct uhci_hcd *uhci, struct uhci_qh *qh)
 631 {
 632         WARN_ON(qh->state == QH_STATE_ACTIVE);
 633
 634         if (qh == uhci->next_qh)
 635                 uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
 636                                 node);
 637         list_move(&qh->node, &uhci->idle_qh_list);
 638         qh->state = QH_STATE_IDLE;
 639
 640         /* Now that the QH is idle, its post_td isn't being used */
 641         if (qh->post_td) {
 642                 uhci_free_td(uhci, qh->post_td);
 643                 qh->post_td = NULL;
 644         }
 645
 646         /* If anyone is waiting for a QH to become idle, wake them up */
 647         if (uhci->num_waiting)
 648                 wake_up_all(&uhci->waitqh);
 649 }
 650
 651 /*
 652  * Find the highest existing bandwidth load for a given phase and period.
 653  */
 654 static int uhci_highest_load(struct uhci_hcd *uhci, int phase, int period)
 655 {
 656         int highest_load = uhci->load[phase];
 657
 658         for (phase += period; phase < MAX_PHASE; phase += period)
 659                 highest_load = max_t(int, highest_load, uhci->load[phase]);
 660         return highest_load;
 661 }
 662
 663 /*
 664  * Set qh->phase to the optimal phase for a periodic transfer and
 665  * check whether the bandwidth requirement is acceptable.
 666  */
 667 static int uhci_check_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh)
 668 {
 669         int minimax_load;
 670
 671         /* Find the optimal phase (unless it is already set) and get
 672          * its load value. */
 673         if (qh->phase >= 0)
 674                 minimax_load = uhci_highest_load(uhci, qh->phase, qh->period);
 675         else {
 676                 int phase, load;
 677                 int max_phase = min_t(int, MAX_PHASE, qh->period);
 678
 679                 qh->phase = 0;
 680                 minimax_load = uhci_highest_load(uhci, qh->phase, qh->period);
 681                 for (phase = 1; phase < max_phase; ++phase) {
 682                         load = uhci_highest_load(uhci, phase, qh->period);
 683                         if (load < minimax_load) {
 684                                 minimax_load = load;
 685                                 qh->phase = phase;
 686                         }
 687                 }
 688         }
 689
 690         /* Maximum allowable periodic bandwidth is 90%, or 900 us per frame */
 691         if (minimax_load + qh->load > 900) {
 692                 dev_dbg(uhci_dev(uhci), "bandwidth allocation failed: "
 693                                 "period %d, phase %d, %d + %d us\n",
 694                                 qh->period, qh->phase, minimax_load, qh->load);
 695                 return -ENOSPC;
 696         }
 697         return 0;
 698 }
 699
 700 /*
 701  * Reserve a periodic QH's bandwidth in the schedule
 702  */
 703 static void uhci_reserve_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh)
 704 {
 705         int i;
 706         int load = qh->load;
 707         char *p = "??";
 708
 709         for (i = qh->phase; i < MAX_PHASE; i += qh->period) {
 710                 uhci->load[i] += load;
 711                 uhci->total_load += load;
 712         }
 713         uhci_to_hcd(uhci)->self.bandwidth_allocated =
 714                         uhci->total_load / MAX_PHASE;
 715         switch (qh->type) {
 716         case USB_ENDPOINT_XFER_INT:
 717                 ++uhci_to_hcd(uhci)->self.bandwidth_int_reqs;
 718                 p = "INT";
 719                 break;
 720         case USB_ENDPOINT_XFER_ISOC:
 721                 ++uhci_to_hcd(uhci)->self.bandwidth_isoc_reqs;
 722                 p = "ISO";
 723                 break;
 724         }
 725         qh->bandwidth_reserved = 1;
 726         dev_dbg(uhci_dev(uhci),
 727                         "%s dev %d ep%02x-%s, period %d, phase %d, %d us\n",
 728                         "reserve", qh->udev->devnum,
 729                         qh->hep->desc.bEndpointAddress, p,
 730                         qh->period, qh->phase, load);
 731 }
 732
 733 /*
 734  * Release a periodic QH's bandwidth reservation
 735  */
 736 static void uhci_release_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh)
 737 {
 738         int i;
 739         int load = qh->load;
 740         char *p = "??";
 741
 742         for (i = qh->phase; i < MAX_PHASE; i += qh->period) {
 743                 uhci->load[i] -= load;
 744                 uhci->total_load -= load;
 745         }
 746         uhci_to_hcd(uhci)->self.bandwidth_allocated =
 747                         uhci->total_load / MAX_PHASE;
 748         switch (qh->type) {
 749         case USB_ENDPOINT_XFER_INT:
 750                 --uhci_to_hcd(uhci)->self.bandwidth_int_reqs;
 751                 p = "INT";
 752                 break;
 753         case USB_ENDPOINT_XFER_ISOC:
 754                 --uhci_to_hcd(uhci)->self.bandwidth_isoc_reqs;
 755                 p = "ISO";
 756                 break;
 757         }
 758         qh->bandwidth_reserved = 0;
 759         dev_dbg(uhci_dev(uhci),
 760                         "%s dev %d ep%02x-%s, period %d, phase %d, %d us\n",
 761                         "release", qh->udev->devnum,
 762                         qh->hep->desc.bEndpointAddress, p,
 763                         qh->period, qh->phase, load);
 764 }
 765
 766 static inline struct urb_priv *uhci_alloc_urb_priv(struct uhci_hcd *uhci,
 767                 struct urb *urb)
 768 {
 769         struct urb_priv *urbp;
 770
 771         urbp = kmem_cache_zalloc(uhci_up_cachep, GFP_ATOMIC);
 772         if (!urbp)
 773                 return NULL;
 774
 775         urbp->urb = urb;
 776         urb->hcpriv = urbp;
 777
 778         INIT_LIST_HEAD(&urbp->node);
 779         INIT_LIST_HEAD(&urbp->td_list);
 780
 781         return urbp;
 782 }
 783
 784 static void uhci_free_urb_priv(struct uhci_hcd *uhci,
 785                 struct urb_priv *urbp)
 786 {
 787         struct uhci_td *td, *tmp;
 788
 789         if (!list_empty(&urbp->node))
 790                 dev_warn(uhci_dev(uhci), "urb %p still on QH's list!\n",
 791                                 urbp->urb);
 792
 793         list_for_each_entry_safe(td, tmp, &urbp->td_list, list) {
 794                 uhci_remove_td_from_urbp(td);
 795                 uhci_free_td(uhci, td);
 796         }
 797
 798         urbp->urb->hcpriv = NULL;
 799         kmem_cache_free(uhci_up_cachep, urbp);
 800 }
 801
 802 /*
 803  * Map status to standard result codes
 804  *
 805  * <status> is (td_status(td) & 0xF60000), a.k.a.
 806  * uhci_status_bits(td_status(td)).
 807  * Note: <status> does not include the TD_CTRL_NAK bit.
 808  * <dir_out> is True for output TDs and False for input TDs.
 809  */
 810 static int uhci_map_status(int status, int dir_out)
 811 {
 812         if (!status)
 813                 return 0;
 814         if (status & TD_CTRL_BITSTUFF)                  /* Bitstuff error */
 815                 return -EPROTO;
 816         if (status & TD_CTRL_CRCTIMEO) {                /* CRC/Timeout */
 817                 if (dir_out)
 818                         return -EPROTO;
 819                 else
 820                         return -EILSEQ;
 821         }
 822         if (status & TD_CTRL_BABBLE)                    /* Babble */
 823                 return -EOVERFLOW;
 824         if (status & TD_CTRL_DBUFERR)                   /* Buffer error */
 825                 return -ENOSR;
 826         if (status & TD_CTRL_STALLED)                   /* Stalled */
 827                 return -EPIPE;
 828         return 0;
 829 }
 830
 831 /*
 832  * Control transfers
 833  */
 834 static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
 835                 struct uhci_qh *qh)
 836 {
 837         struct uhci_td *td;
 838         unsigned long destination, status;
 839         int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize);
 840         int len = urb->transfer_buffer_length;
 841         dma_addr_t data = urb->transfer_dma;
 842         __le32 *plink;
 843         struct urb_priv *urbp = urb->hcpriv;
 844         int skel;
 845
 846         /* The "pipe" thing contains the destination in bits 8--18 */
 847         destination = (urb->pipe & PIPE_DEVEP_MASK) | USB_PID_SETUP;
 848
 849         /* 3 errors, dummy TD remains inactive */
 850         status = uhci_maxerr(3);
 851         if (urb->dev->speed == USB_SPEED_LOW)
 852                 status |= TD_CTRL_LS;
 853
 854         /*
 855          * Build the TD for the control request setup packet
 856          */
 857         td = qh->dummy_td;
 858         uhci_add_td_to_urbp(td, urbp);
 859         uhci_fill_td(td, status, destination | uhci_explen(8),
 860                         urb->setup_dma);
 861         plink = &td->link;
 862         status |= TD_CTRL_ACTIVE;
 863
 864         /*
 865          * If direction is "send", change the packet ID from SETUP (0x2D)
 866          * to OUT (0xE1).  Else change it from SETUP to IN (0x69) and
 867          * set Short Packet Detect (SPD) for all data packets.
 868          */
 869         if (usb_pipeout(urb->pipe))
 870                 destination ^= (USB_PID_SETUP ^ USB_PID_OUT);
 871         else {
 872                 destination ^= (USB_PID_SETUP ^ USB_PID_IN);
 873                 status |= TD_CTRL_SPD;
 874         }
 875
 876         /*
 877          * Build the DATA TDs
 878          */
 879         while (len > 0) {
 880                 int pktsze = min(len, maxsze);
 881
 882                 td = uhci_alloc_td(uhci);
 883                 if (!td)
 884                         goto nomem;
 885                 *plink = LINK_TO_TD(td);
 886
 887                 /* Alternate Data0/1 (start with Data1) */
 888                 destination ^= TD_TOKEN_TOGGLE;
 889
 890                 uhci_add_td_to_urbp(td, urbp);
 891                 uhci_fill_td(td, status, destination | uhci_explen(pktsze),
 892                                 data);
 893                 plink = &td->link;
 894
 895                 data += pktsze;
 896                 len -= pktsze;
 897         }
 898
 899         /*
 900          * Build the final TD for control status
 901          */
 902         td = uhci_alloc_td(uhci);
 903         if (!td)
 904                 goto nomem;
 905         *plink = LINK_TO_TD(td);
 906
 907         /*
 908          * It's IN if the pipe is an output pipe or we're not expecting
 909          * data back.
 910          */
 911         destination &= ~TD_TOKEN_PID_MASK;
 912         if (usb_pipeout(urb->pipe) || !urb->transfer_buffer_length)
 913                 destination |= USB_PID_IN;
 914         else
 915                 destination |= USB_PID_OUT;
 916
 917         destination |= TD_TOKEN_TOGGLE;         /* End in Data1 */
 918
 919         status &= ~TD_CTRL_SPD;
 920
 921         uhci_add_td_to_urbp(td, urbp);
 922         uhci_fill_td(td, status | TD_CTRL_IOC,
 923                         destination | uhci_explen(0), 0);
 924         plink = &td->link;
 925
 926         /*
 927          * Build the new dummy TD and activate the old one
 928          */
 929         td = uhci_alloc_td(uhci);
 930         if (!td)
 931                 goto nomem;
 932         *plink = LINK_TO_TD(td);
 933
 934         uhci_fill_td(td, 0, USB_PID_OUT | uhci_explen(0), 0);
 935         wmb();
 936         qh->dummy_td->status |= __constant_cpu_to_le32(TD_CTRL_ACTIVE);
 937         qh->dummy_td = td;
 938
 939         /* Low-speed transfers get a different queue, and won't hog the bus.
 940          * Also, some devices enumerate better without FSBR; the easiest way
 941          * to do that is to put URBs on the low-speed queue while the device
 942          * isn't in the CONFIGURED state. */
 943         if (urb->dev->speed == USB_SPEED_LOW ||
 944                         urb->dev->state != USB_STATE_CONFIGURED)
 945                 skel = SKEL_LS_CONTROL;
 946         else {
 947                 skel = SKEL_FS_CONTROL;
 948                 uhci_add_fsbr(uhci, urb);
 949         }
 950         if (qh->state != QH_STATE_ACTIVE)
 951                 qh->skel = skel;
 952
 953         urb->actual_length = -8;        /* Account for the SETUP packet */
 954         return 0;
 955
 956 nomem:
 957         /* Remove the dummy TD from the td_list so it doesn't get freed */
 958         uhci_remove_td_from_urbp(qh->dummy_td);
 959         return -ENOMEM;
 960 }
 961
 962 /*
 963  * Common submit for bulk and interrupt
 964  */
 965 static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb,
 966                 struct uhci_qh *qh)
 967 {
 968         struct uhci_td *td;
 969         unsigned long destination, status;
 970         int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize);
 971         int len = urb->transfer_buffer_length;
 972         dma_addr_t data = urb->transfer_dma;
 973         __le32 *plink;
 974         struct urb_priv *urbp = urb->hcpriv;
 975         unsigned int toggle;
 976
 977         if (len < 0)
 978                 return -EINVAL;
 979
 980         /* The "pipe" thing contains the destination in bits 8--18 */
 981         destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
 982         toggle = usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
 983                          usb_pipeout(urb->pipe));
 984
 985         /* 3 errors, dummy TD remains inactive */
 986         status = uhci_maxerr(3);
 987         if (urb->dev->speed == USB_SPEED_LOW)
 988                 status |= TD_CTRL_LS;
 989         if (usb_pipein(urb->pipe))
 990                 status |= TD_CTRL_SPD;
 991
 992         /*
 993          * Build the DATA TDs
 994          */
 995         plink = NULL;
 996         td = qh->dummy_td;
 997         do {    /* Allow zero length packets */
 998                 int pktsze = maxsze;
 999
1000                 if (len <= pktsze) {            /* The last packet */
1001                         pktsze = len;
1002                         if (!(urb->transfer_flags & URB_SHORT_NOT_OK))
1003                                 status &= ~TD_CTRL_SPD;
1004                 }
1005
1006                 if (plink) {
1007                         td = uhci_alloc_td(uhci);
1008                         if (!td)
1009                                 goto nomem;
1010                         *plink = LINK_TO_TD(td);
1011                 }
1012                 uhci_add_td_to_urbp(td, urbp);
1013                 uhci_fill_td(td, status,
1014                                 destination | uhci_explen(pktsze) |
1015                                         (toggle << TD_TOKEN_TOGGLE_SHIFT),
1016                                 data);
1017                 plink = &td->link;
1018                 status |= TD_CTRL_ACTIVE;
1019
1020                 data += pktsze;
1021                 len -= maxsze;
1022                 toggle ^= 1;
1023         } while (len > 0);
1024
1025         /*
1026          * URB_ZERO_PACKET means adding a 0-length packet, if direction
1027          * is OUT and the transfer_length was an exact multiple of maxsze,
1028          * hence (len = transfer_length - N * maxsze) == 0
1029          * however, if transfer_length == 0, the zero packet was already
1030          * prepared above.
1031          */
1032         if ((urb->transfer_flags & URB_ZERO_PACKET) &&
1033                         usb_pipeout(urb->pipe) && len == 0 &&
1034                         urb->transfer_buffer_length > 0) {
1035                 td = uhci_alloc_td(uhci);
1036                 if (!td)
1037                         goto nomem;
1038                 *plink = LINK_TO_TD(td);
1039
1040                 uhci_add_td_to_urbp(td, urbp);
1041                 uhci_fill_td(td, status,
1042                                 destination | uhci_explen(0) |
1043                                         (toggle << TD_TOKEN_TOGGLE_SHIFT),
1044                                 data);
1045                 plink = &td->link;
1046
1047                 toggle ^= 1;
1048         }
1049
1050         /* Set the interrupt-on-completion flag on the last packet.
1051          * A more-or-less typical 4 KB URB (= size of one memory page)
1052          * will require about 3 ms to transfer; that's a little on the
1053          * fast side but not enough to justify delaying an interrupt
1054          * more than 2 or 3 URBs, so we will ignore the URB_NO_INTERRUPT
1055          * flag setting. */
1056         td->status |= __constant_cpu_to_le32(TD_CTRL_IOC);
1057
1058         /*
1059          * Build the new dummy TD and activate the old one
1060          */
1061         td = uhci_alloc_td(uhci);
1062         if (!td)
1063                 goto nomem;
1064         *plink = LINK_TO_TD(td);
1065
1066         uhci_fill_td(td, 0, USB_PID_OUT | uhci_explen(0), 0);
1067         wmb();
1068         qh->dummy_td->status |= __constant_cpu_to_le32(TD_CTRL_ACTIVE);
1069         qh->dummy_td = td;
1070
1071         usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
1072                         usb_pipeout(urb->pipe), toggle);
1073         return 0;
1074
1075 nomem:
1076         /* Remove the dummy TD from the td_list so it doesn't get freed */
1077         uhci_remove_td_from_urbp(qh->dummy_td);
1078         return -ENOMEM;
1079 }
1080
1081 static int uhci_submit_bulk(struct uhci_hcd *uhci, struct urb *urb,
1082                 struct uhci_qh *qh)
1083 {
1084         int ret;
1085
1086         /* Can't have low-speed bulk transfers */
1087         if (urb->dev->speed == USB_SPEED_LOW)
1088                 return -EINVAL;
1089
1090         if (qh->state != QH_STATE_ACTIVE)
1091                 qh->skel = SKEL_BULK;
1092         ret = uhci_submit_common(uhci, urb, qh);
1093         if (ret == 0)
1094                 uhci_add_fsbr(uhci, urb);
1095         return ret;
1096 }
1097
1098 static int uhci_submit_interrupt(struct uhci_hcd *uhci, struct urb *urb,
1099                 struct uhci_qh *qh)
1100 {
1101         int ret;
1102
1103         /* USB 1.1 interrupt transfers only involve one packet per interval.
1104          * Drivers can submit URBs of any length, but longer ones will need
1105          * multiple intervals to complete.
1106          */
1107
1108         if (!qh->bandwidth_reserved) {
1109                 int exponent;
1110
1111                 /* Figure out which power-of-two queue to use */
1112                 for (exponent = 7; exponent >= 0; --exponent) {
1113                         if ((1 << exponent) <= urb->interval)
1114                                 break;
1115                 }
1116                 if (exponent < 0)
1117                         return -EINVAL;
1118                 qh->period = 1 << exponent;
1119                 qh->skel = SKEL_INDEX(exponent);
1120
1121                 /* For now, interrupt phase is fixed by the layout
1122                  * of the QH lists. */
1123                 qh->phase = (qh->period / 2) & (MAX_PHASE - 1);
1124                 ret = uhci_check_bandwidth(uhci, qh);
1125                 if (ret)
1126                         return ret;
1127         } else if (qh->period > urb->interval)
1128                 return -EINVAL;         /* Can't decrease the period */
1129
1130         ret = uhci_submit_common(uhci, urb, qh);
1131         if (ret == 0) {
1132                 urb->interval = qh->period;
1133                 if (!qh->bandwidth_reserved)
1134                         uhci_reserve_bandwidth(uhci, qh);
1135         }
1136         return ret;
1137 }
1138
1139 /*
1140  * Fix up the data structures following a short transfer
1141  */
1142 static int uhci_fixup_short_transfer(struct uhci_hcd *uhci,
1143                 struct uhci_qh *qh, struct urb_priv *urbp)
1144 {
1145         struct uhci_td *td;
1146         struct list_head *tmp;
1147         int ret;
1148
1149         td = list_entry(urbp->td_list.prev, struct uhci_td, list);
1150         if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
1151
1152                 /* When a control transfer is short, we have to restart
1153                  * the queue at the status stage transaction, which is
1154                  * the last TD. */
1155                 WARN_ON(list_empty(&urbp->td_list));
1156                 qh->element = LINK_TO_TD(td);
1157                 tmp = td->list.prev;
1158                 ret = -EINPROGRESS;
1159
1160         } else {
1161
1162                 /* When a bulk/interrupt transfer is short, we have to
1163                  * fix up the toggles of the following URBs on the queue
1164                  * before restarting the queue at the next URB. */
1165                 qh->initial_toggle = uhci_toggle(td_token(qh->post_td)) ^ 1;
1166                 uhci_fixup_toggles(qh, 1);
1167
1168                 if (list_empty(&urbp->td_list))
1169                         td = qh->post_td;
1170                 qh->element = td->link;
1171                 tmp = urbp->td_list.prev;
1172                 ret = 0;
1173         }
1174
1175         /* Remove all the TDs we skipped over, from tmp back to the start */
1176         while (tmp != &urbp->td_list) {
1177                 td = list_entry(tmp, struct uhci_td, list);
1178                 tmp = tmp->prev;
1179
1180                 uhci_remove_td_from_urbp(td);
1181                 uhci_free_td(uhci, td);
1182         }
1183         return ret;
1184 }
1185
1186 /*
1187  * Common result for control, bulk, and interrupt
1188  */
1189 static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
1190 {
1191         struct urb_priv *urbp = urb->hcpriv;
1192         struct uhci_qh *qh = urbp->qh;
1193         struct uhci_td *td, *tmp;
1194         unsigned status;
1195         int ret = 0;
1196
1197         list_for_each_entry_safe(td, tmp, &urbp->td_list, list) {
1198                 unsigned int ctrlstat;
1199                 int len;
1200
1201                 ctrlstat = td_status(td);
1202                 status = uhci_status_bits(ctrlstat);
1203                 if (status & TD_CTRL_ACTIVE)
1204                         return -EINPROGRESS;
1205
1206                 len = uhci_actual_length(ctrlstat);
1207                 urb->actual_length += len;
1208
1209                 if (status) {
1210                         ret = uhci_map_status(status,
1211                                         uhci_packetout(td_token(td)));
1212                         if ((debug == 1 && ret != -EPIPE) || debug > 1) {
1213                                 /* Some debugging code */
1214                                 dev_dbg(&urb->dev->dev,
1215                                                 "%s: failed with status %x\n",
1216                                                 __FUNCTION__, status);
1217
1218                                 if (debug > 1 && errbuf) {
1219                                         /* Print the chain for debugging */
1220                                         uhci_show_qh(urbp->qh, errbuf,
1221                                                         ERRBUF_LEN, 0);
1222                                         lprintk(errbuf);
1223                                 }
1224                         }
1225
1226                 } else if (len < uhci_expected_length(td_token(td))) {
1227
1228                         /* We received a short packet */
1229                         if (urb->transfer_flags & URB_SHORT_NOT_OK)
1230                                 ret = -EREMOTEIO;
1231
1232                         /* Fixup needed only if this isn't the URB's last TD */
1233                         else if (&td->list != urbp->td_list.prev)
1234                                 ret = 1;
1235                 }
1236
1237                 uhci_remove_td_from_urbp(td);
1238                 if (qh->post_td)
1239                         uhci_free_td(uhci, qh->post_td);
1240                 qh->post_td = td;
1241
1242                 if (ret != 0)
1243                         goto err;
1244         }
1245         return ret;
1246
1247 err:
1248         if (ret < 0) {
1249                 /* In case a control transfer gets an error
1250                  * during the setup stage */
1251                 urb->actual_length = max(urb->actual_length, 0);
1252
1253                 /* Note that the queue has stopped and save
1254                  * the next toggle value */
1255                 qh->element = UHCI_PTR_TERM;
1256                 qh->is_stopped = 1;
1257                 qh->needs_fixup = (qh->type != USB_ENDPOINT_XFER_CONTROL);
1258                 qh->initial_toggle = uhci_toggle(td_token(td)) ^
1259                                 (ret == -EREMOTEIO);
1260
1261         } else          /* Short packet received */
1262                 ret = uhci_fixup_short_transfer(uhci, qh, urbp);
1263         return ret;
1264 }
1265
1266 /*
1267  * Isochronous transfers
1268  */
1269 static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb,
1270                 struct uhci_qh *qh)
1271 {
1272         struct uhci_td *td = NULL;      /* Since urb->number_of_packets > 0 */
1273         int i, frame;
1274         unsigned long destination, status;
1275         struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
1276
1277         /* Values must not be too big (could overflow below) */
1278         if (urb->interval >= UHCI_NUMFRAMES ||
1279                         urb->number_of_packets >= UHCI_NUMFRAMES)
1280                 return -EFBIG;
1281
1282         /* Check the period and figure out the starting frame number */
1283         if (!qh->bandwidth_reserved) {
1284                 qh->period = urb->interval;
1285                 if (urb->transfer_flags & URB_ISO_ASAP) {
1286                         qh->phase = -1;         /* Find the best phase */
1287                         i = uhci_check_bandwidth(uhci, qh);
1288                         if (i)
1289                                 return i;
1290
1291                         /* Allow a little time to allocate the TDs */
1292                         uhci_get_current_frame_number(uhci);
1293                         frame = uhci->frame_number + 10;
1294
1295                         /* Move forward to the first frame having the
1296                          * correct phase */
1297                         urb->start_frame = frame + ((qh->phase - frame) &
1298                                         (qh->period - 1));
1299                 } else {
1300                         i = urb->start_frame - uhci->last_iso_frame;
1301                         if (i <= 0 || i >= UHCI_NUMFRAMES)
1302                                 return -EINVAL;
1303                         qh->phase = urb->start_frame & (qh->period - 1);
1304                         i = uhci_check_bandwidth(uhci, qh);
1305                         if (i)
1306                                 return i;
1307                 }
1308
1309         } else if (qh->period != urb->interval) {
1310                 return -EINVAL;         /* Can't change the period */
1311
1312         } else {        /* Pick up where the last URB leaves off */
1313                 if (list_empty(&qh->queue)) {
1314                         frame = qh->iso_frame;
1315                 } else {
1316                         struct urb *lurb;
1317
1318                         lurb = list_entry(qh->queue.prev,
1319                                         struct urb_priv, node)->urb;
1320                         frame = lurb->start_frame +
1321                                         lurb->number_of_packets *
1322                                         lurb->interval;
1323                 }
1324                 if (urb->transfer_flags & URB_ISO_ASAP)
1325                         urb->start_frame = frame;
1326                 else if (urb->start_frame != frame)
1327                         return -EINVAL;
1328         }
1329
1330         /* Make sure we won't have to go too far into the future */
1331         if (uhci_frame_before_eq(uhci->last_iso_frame + UHCI_NUMFRAMES,
1332                         urb->start_frame + urb->number_of_packets *
1333                                 urb->interval))
1334                 return -EFBIG;
1335
1336         status = TD_CTRL_ACTIVE | TD_CTRL_IOS;
1337         destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
1338
1339         for (i = 0; i < urb->number_of_packets; i++) {
1340                 td = uhci_alloc_td(uhci);
1341                 if (!td)
1342                         return -ENOMEM;
1343
1344                 uhci_add_td_to_urbp(td, urbp);
1345                 uhci_fill_td(td, status, destination |
1346                                 uhci_explen(urb->iso_frame_desc[i].length),
1347                                 urb->transfer_dma +
1348                                         urb->iso_frame_desc[i].offset);
1349         }
1350
1351         /* Set the interrupt-on-completion flag on the last packet. */
1352         td->status |= __constant_cpu_to_le32(TD_CTRL_IOC);
1353
1354         /* Add the TDs to the frame list */
1355         frame = urb->start_frame;
1356         list_for_each_entry(td, &urbp->td_list, list) {
1357                 uhci_insert_td_in_frame_list(uhci, td, frame);
1358                 frame += qh->period;
1359         }
1360
1361         if (list_empty(&qh->queue)) {
1362                 qh->iso_packet_desc = &urb->iso_frame_desc[0];
1363                 qh->iso_frame = urb->start_frame;
1364                 qh->iso_status = 0;
1365         }
1366
1367         qh->skel = SKEL_ISO;
1368         if (!qh->bandwidth_reserved)
1369                 uhci_reserve_bandwidth(uhci, qh);
1370         return 0;
1371 }
1372
1373 static int uhci_result_isochronous(struct uhci_hcd *uhci, struct urb *urb)
1374 {
1375         struct uhci_td *td, *tmp;
1376         struct urb_priv *urbp = urb->hcpriv;
1377         struct uhci_qh *qh = urbp->qh;
1378
1379         list_for_each_entry_safe(td, tmp, &urbp->td_list, list) {
1380                 unsigned int ctrlstat;
1381                 int status;
1382                 int actlength;
1383
1384                 if (uhci_frame_before_eq(uhci->cur_iso_frame, qh->iso_frame))
1385                         return -EINPROGRESS;
1386
1387                 uhci_remove_tds_from_frame(uhci, qh->iso_frame);
1388
1389                 ctrlstat = td_status(td);
1390                 if (ctrlstat & TD_CTRL_ACTIVE) {
1391                         status = -EXDEV;        /* TD was added too late? */
1392                 } else {
1393                         status = uhci_map_status(uhci_status_bits(ctrlstat),
1394                                         usb_pipeout(urb->pipe));
1395                         actlength = uhci_actual_length(ctrlstat);
1396
1397                         urb->actual_length += actlength;
1398                         qh->iso_packet_desc->actual_length = actlength;
1399                         qh->iso_packet_desc->status = status;
1400                 }
1401
1402                 if (status) {
1403                         urb->error_count++;
1404                         qh->iso_status = status;
1405                 }
1406
1407                 uhci_remove_td_from_urbp(td);
1408                 uhci_free_td(uhci, td);
1409                 qh->iso_frame += qh->period;
1410                 ++qh->iso_packet_desc;
1411         }
1412         return qh->iso_status;
1413 }
1414
1415 static int uhci_urb_enqueue(struct usb_hcd *hcd,
1416                 struct usb_host_endpoint *hep,
1417                 struct urb *urb, gfp_t mem_flags)
1418 {
1419         int ret;
1420         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
1421         unsigned long flags;
1422         struct urb_priv *urbp;
1423         struct uhci_qh *qh;
1424
1425         spin_lock_irqsave(&uhci->lock, flags);
1426
1427         ret = urb->status;
1428         if (ret != -EINPROGRESS)                /* URB already unlinked! */
1429                 goto done;
1430
1431         ret = -ENOMEM;
1432         urbp = uhci_alloc_urb_priv(uhci, urb);
1433         if (!urbp)
1434                 goto done;
1435
1436         if (hep->hcpriv)
1437                 qh = (struct uhci_qh *) hep->hcpriv;
1438         else {
1439                 qh = uhci_alloc_qh(uhci, urb->dev, hep);
1440                 if (!qh)
1441                         goto err_no_qh;
1442         }
1443         urbp->qh = qh;
1444
1445         switch (qh->type) {
1446         case USB_ENDPOINT_XFER_CONTROL:
1447                 ret = uhci_submit_control(uhci, urb, qh);
1448                 break;
1449         case USB_ENDPOINT_XFER_BULK:
1450                 ret = uhci_submit_bulk(uhci, urb, qh);
1451                 break;
1452         case USB_ENDPOINT_XFER_INT:
1453                 ret = uhci_submit_interrupt(uhci, urb, qh);
1454                 break;
1455         case USB_ENDPOINT_XFER_ISOC:
1456                 urb->error_count = 0;
1457                 ret = uhci_submit_isochronous(uhci, urb, qh);
1458                 break;
1459         }
1460         if (ret != 0)
1461                 goto err_submit_failed;
1462
1463         /* Add this URB to the QH */
1464         urbp->qh = qh;
1465         list_add_tail(&urbp->node, &qh->queue);
1466
1467         /* If the new URB is the first and only one on this QH then either
1468          * the QH is new and idle or else it's unlinked and waiting to
1469          * become idle, so we can activate it right away.  But only if the
1470          * queue isn't stopped. */
1471         if (qh->queue.next == &urbp->node && !qh->is_stopped) {
1472                 uhci_activate_qh(uhci, qh);
1473                 uhci_urbp_wants_fsbr(uhci, urbp);
1474         }
1475         goto done;
1476
1477 err_submit_failed:
1478         if (qh->state == QH_STATE_IDLE)
1479                 uhci_make_qh_idle(uhci, qh);    /* Reclaim unused QH */
1480
1481 err_no_qh:
1482         uhci_free_urb_priv(uhci, urbp);
1483
1484 done:
1485         spin_unlock_irqrestore(&uhci->lock, flags);
1486         return ret;
1487 }
1488
1489 static int uhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb)
1490 {
1491         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
1492         unsigned long flags;
1493         struct urb_priv *urbp;
1494         struct uhci_qh *qh;
1495
1496         spin_lock_irqsave(&uhci->lock, flags);
1497         urbp = urb->hcpriv;
1498         if (!urbp)                      /* URB was never linked! */
1499                 goto done;
1500         qh = urbp->qh;
1501
1502         /* Remove Isochronous TDs from the frame list ASAP */
1503         if (qh->type == USB_ENDPOINT_XFER_ISOC) {
1504                 uhci_unlink_isochronous_tds(uhci, urb);
1505                 mb();
1506
1507                 /* If the URB has already started, update the QH unlink time */
1508                 uhci_get_current_frame_number(uhci);
1509                 if (uhci_frame_before_eq(urb->start_frame, uhci->frame_number))
1510                         qh->unlink_frame = uhci->frame_number;
1511         }
1512
1513         uhci_unlink_qh(uhci, qh);
1514
1515 done:
1516         spin_unlock_irqrestore(&uhci->lock, flags);
1517         return 0;
1518 }
1519
1520 /*
1521  * Finish unlinking an URB and give it back
1522  */
1523 static void uhci_giveback_urb(struct uhci_hcd *uhci, struct uhci_qh *qh,
1524                 struct urb *urb)
1525 __releases(uhci->lock)
1526 __acquires(uhci->lock)
1527 {
1528         struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
1529
1530         /* When giving back the first URB in an Isochronous queue,
1531          * reinitialize the QH's iso-related members for the next URB. */
1532         if (qh->type == USB_ENDPOINT_XFER_ISOC &&
1533                         urbp->node.prev == &qh->queue &&
1534                         urbp->node.next != &qh->queue) {
1535                 struct urb *nurb = list_entry(urbp->node.next,
1536                                 struct urb_priv, node)->urb;
1537
1538                 qh->iso_packet_desc = &nurb->iso_frame_desc[0];
1539                 qh->iso_frame = nurb->start_frame;
1540                 qh->iso_status = 0;
1541         }
1542
1543         /* Take the URB off the QH's queue.  If the queue is now empty,
1544          * this is a perfect time for a toggle fixup. */
1545         list_del_init(&urbp->node);
1546         if (list_empty(&qh->queue) && qh->needs_fixup) {
1547                 usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
1548                                 usb_pipeout(urb->pipe), qh->initial_toggle);
1549                 qh->needs_fixup = 0;
1550         }
1551
1552         uhci_free_urb_priv(uhci, urbp);
1553
1554         spin_unlock(&uhci->lock);
1555         usb_hcd_giveback_urb(uhci_to_hcd(uhci), urb);
1556         spin_lock(&uhci->lock);
1557
1558         /* If the queue is now empty, we can unlink the QH and give up its
1559          * reserved bandwidth. */
1560         if (list_empty(&qh->queue)) {
1561                 uhci_unlink_qh(uhci, qh);
1562                 if (qh->bandwidth_reserved)
1563                         uhci_release_bandwidth(uhci, qh);
1564         }
1565 }
1566
1567 /*
1568  * Scan the URBs in a QH's queue
1569  */
1570 #define QH_FINISHED_UNLINKING(qh)                       \
1571                 (qh->state == QH_STATE_UNLINKING &&     \
1572                 uhci->frame_number + uhci->is_stopped != qh->unlink_frame)
1573
1574 static void uhci_scan_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
1575 {
1576         struct urb_priv *urbp;
1577         struct urb *urb;
1578         int status;
1579
1580         while (!list_empty(&qh->queue)) {
1581                 urbp = list_entry(qh->queue.next, struct urb_priv, node);
1582                 urb = urbp->urb;
1583
1584                 if (qh->type == USB_ENDPOINT_XFER_ISOC)
1585                         status = uhci_result_isochronous(uhci, urb);
1586                 else
1587                         status = uhci_result_common(uhci, urb);
1588                 if (status == -EINPROGRESS)
1589                         break;
1590
1591                 spin_lock(&urb->lock);
1592                 if (urb->status == -EINPROGRESS)        /* Not dequeued */
1593                         urb->status = status;
1594                 else
1595                         status = ECONNRESET;            /* Not -ECONNRESET */
1596                 spin_unlock(&urb->lock);
1597
1598                 /* Dequeued but completed URBs can't be given back unless
1599                  * the QH is stopped or has finished unlinking. */
1600                 if (status == ECONNRESET) {
1601                         if (QH_FINISHED_UNLINKING(qh))
1602                                 qh->is_stopped = 1;
1603                         else if (!qh->is_stopped)
1604                                 return;
1605                 }
1606
1607                 uhci_giveback_urb(uhci, qh, urb);
1608                 if (status < 0 && qh->type != USB_ENDPOINT_XFER_ISOC)
1609                         break;
1610         }
1611
1612         /* If the QH is neither stopped nor finished unlinking (normal case),
1613          * our work here is done. */
1614         if (QH_FINISHED_UNLINKING(qh))
1615                 qh->is_stopped = 1;
1616         else if (!qh->is_stopped)
1617                 return;
1618
1619         /* Otherwise give back each of the dequeued URBs */
1620 restart:
1621         list_for_each_entry(urbp, &qh->queue, node) {
1622                 urb = urbp->urb;
1623                 if (urb->status != -EINPROGRESS) {
1624
1625                         /* Fix up the TD links and save the toggles for
1626                          * non-Isochronous queues.  For Isochronous queues,
1627                          * test for too-recent dequeues. */
1628                         if (!uhci_cleanup_queue(uhci, qh, urb)) {
1629                                 qh->is_stopped = 0;
1630                                 return;
1631                         }
1632                         uhci_giveback_urb(uhci, qh, urb);
1633                         goto restart;
1634                 }
1635         }
1636         qh->is_stopped = 0;
1637
1638         /* There are no more dequeued URBs.  If there are still URBs on the
1639          * queue, the QH can now be re-activated. */
1640         if (!list_empty(&qh->queue)) {
1641                 if (qh->needs_fixup)
1642                         uhci_fixup_toggles(qh, 0);
1643
1644                 /* If the first URB on the queue wants FSBR but its time
1645                  * limit has expired, set the next TD to interrupt on
1646                  * completion before reactivating the QH. */
1647                 urbp = list_entry(qh->queue.next, struct urb_priv, node);
1648                 if (urbp->fsbr && qh->wait_expired) {
1649                         struct uhci_td *td = list_entry(urbp->td_list.next,
1650                                         struct uhci_td, list);
1651
1652                         td->status |= __cpu_to_le32(TD_CTRL_IOC);
1653                 }
1654
1655                 uhci_activate_qh(uhci, qh);
1656         }
1657
1658         /* The queue is empty.  The QH can become idle if it is fully
1659          * unlinked. */
1660         else if (QH_FINISHED_UNLINKING(qh))
1661                 uhci_make_qh_idle(uhci, qh);
1662 }
1663
1664 /*
1665  * Check for queues that have made some forward progress.
1666  * Returns 0 if the queue is not Isochronous, is ACTIVE, and
1667  * has not advanced since last examined; 1 otherwise.
1668  *
1669  * Early Intel controllers have a bug which causes qh->element sometimes
1670  * not to advance when a TD completes successfully.  The queue remains
1671  * stuck on the inactive completed TD.  We detect such cases and advance
1672  * the element pointer by hand.
1673  */
1674 static int uhci_advance_check(struct uhci_hcd *uhci, struct uhci_qh *qh)
1675 {
1676         struct urb_priv *urbp = NULL;
1677         struct uhci_td *td;
1678         int ret = 1;
1679         unsigned status;
1680
1681         if (qh->type == USB_ENDPOINT_XFER_ISOC)
1682                 goto done;
1683
1684         /* Treat an UNLINKING queue as though it hasn't advanced.
1685          * This is okay because reactivation will treat it as though
1686          * it has advanced, and if it is going to become IDLE then
1687          * this doesn't matter anyway.  Furthermore it's possible
1688          * for an UNLINKING queue not to have any URBs at all, or
1689          * for its first URB not to have any TDs (if it was dequeued
1690          * just as it completed).  So it's not easy in any case to
1691          * test whether such queues have advanced. */
1692         if (qh->state != QH_STATE_ACTIVE) {
1693                 urbp = NULL;
1694                 status = 0;
1695
1696         } else {
1697                 urbp = list_entry(qh->queue.next, struct urb_priv, node);
1698                 td = list_entry(urbp->td_list.next, struct uhci_td, list);
1699                 status = td_status(td);
1700                 if (!(status & TD_CTRL_ACTIVE)) {
1701
1702                         /* We're okay, the queue has advanced */
1703                         qh->wait_expired = 0;
1704                         qh->advance_jiffies = jiffies;
1705                         goto done;
1706                 }
1707                 ret = 0;
1708         }
1709
1710         /* The queue hasn't advanced; check for timeout */
1711         if (qh->wait_expired)
1712                 goto done;
1713
1714         if (time_after(jiffies, qh->advance_jiffies + QH_WAIT_TIMEOUT)) {
1715
1716                 /* Detect the Intel bug and work around it */
1717                 if (qh->post_td && qh_element(qh) == LINK_TO_TD(qh->post_td)) {
1718                         qh->element = qh->post_td->link;
1719                         qh->advance_jiffies = jiffies;
1720                         ret = 1;
1721                         goto done;
1722                 }
1723
1724                 qh->wait_expired = 1;
1725
1726                 /* If the current URB wants FSBR, unlink it temporarily
1727                  * so that we can safely set the next TD to interrupt on
1728                  * completion.  That way we'll know as soon as the queue
1729                  * starts moving again. */
1730                 if (urbp && urbp->fsbr && !(status & TD_CTRL_IOC))
1731                         uhci_unlink_qh(uhci, qh);
1732
1733         } else {
1734                 /* Unmoving but not-yet-expired queues keep FSBR alive */
1735                 if (urbp)
1736                         uhci_urbp_wants_fsbr(uhci, urbp);
1737         }
1738
1739 done:
1740         return ret;
1741 }
1742
1743 /*
1744  * Process events in the schedule, but only in one thread at a time
1745  */
1746 static void uhci_scan_schedule(struct uhci_hcd *uhci)
1747 {
1748         int i;
1749         struct uhci_qh *qh;
1750
1751         /* Don't allow re-entrant calls */
1752         if (uhci->scan_in_progress) {
1753                 uhci->need_rescan = 1;
1754                 return;
1755         }
1756         uhci->scan_in_progress = 1;
1757 rescan:
1758         uhci->need_rescan = 0;
1759         uhci->fsbr_is_wanted = 0;
1760
1761         uhci_clear_next_interrupt(uhci);
1762         uhci_get_current_frame_number(uhci);
1763         uhci->cur_iso_frame = uhci->frame_number;
1764
1765         /* Go through all the QH queues and process the URBs in each one */
1766         for (i = 0; i < UHCI_NUM_SKELQH - 1; ++i) {
1767                 uhci->next_qh = list_entry(uhci->skelqh[i]->node.next,
1768                                 struct uhci_qh, node);
1769                 while ((qh = uhci->next_qh) != uhci->skelqh[i]) {
1770                         uhci->next_qh = list_entry(qh->node.next,
1771                                         struct uhci_qh, node);
1772
1773                         if (uhci_advance_check(uhci, qh)) {
1774                                 uhci_scan_qh(uhci, qh);
1775                                 if (qh->state == QH_STATE_ACTIVE) {
1776                                         uhci_urbp_wants_fsbr(uhci,
1777         list_entry(qh->queue.next, struct urb_priv, node));
1778                                 }
1779                         }
1780                 }
1781         }
1782
1783         uhci->last_iso_frame = uhci->cur_iso_frame;
1784         if (uhci->need_rescan)
1785                 goto rescan;
1786         uhci->scan_in_progress = 0;
1787
1788         if (uhci->fsbr_is_on && !uhci->fsbr_is_wanted &&
1789                         !uhci->fsbr_expiring) {
1790                 uhci->fsbr_expiring = 1;
1791                 mod_timer(&uhci->fsbr_timer, jiffies + FSBR_OFF_DELAY);
1792         }
1793
1794         if (list_empty(&uhci->skel_unlink_qh->node))
1795                 uhci_clear_next_interrupt(uhci);
1796         else
1797                 uhci_set_next_interrupt(uhci);
1798 }