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 2004-2005 Alan Stern, stern@rowland.harvard.edu
  17  */
  18
  19 static void uhci_free_pending_tds(struct uhci_hcd *uhci);
  20
  21 /*
  22  * Technically, updating td->status here is a race, but it's not really a
  23  * problem. The worst that can happen is that we set the IOC bit again
  24  * generating a spurious interrupt. We could fix this by creating another
  25  * QH and leaving the IOC bit always set, but then we would have to play
  26  * games with the FSBR code to make sure we get the correct order in all
  27  * the cases. I don't think it's worth the effort
  28  */
  29 static void uhci_set_next_interrupt(struct uhci_hcd *uhci)
  30 {
  31         if (uhci->is_stopped)
  32                 mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies);
  33         uhci->term_td->status |= cpu_to_le32(TD_CTRL_IOC);
  34 }
  35
  36 static inline void uhci_clear_next_interrupt(struct uhci_hcd *uhci)
  37 {
  38         uhci->term_td->status &= ~cpu_to_le32(TD_CTRL_IOC);
  39 }
  40
  41 static struct uhci_td *uhci_alloc_td(struct uhci_hcd *uhci)
  42 {
  43         dma_addr_t dma_handle;
  44         struct uhci_td *td;
  45
  46         td = dma_pool_alloc(uhci->td_pool, GFP_ATOMIC, &dma_handle);
  47         if (!td)
  48                 return NULL;
  49
  50         td->dma_handle = dma_handle;
  51         td->frame = -1;
  52
  53         INIT_LIST_HEAD(&td->list);
  54         INIT_LIST_HEAD(&td->remove_list);
  55         INIT_LIST_HEAD(&td->fl_list);
  56
  57         return td;
  58 }
  59
  60 static void uhci_free_td(struct uhci_hcd *uhci, struct uhci_td *td)
  61 {
  62         if (!list_empty(&td->list))
  63                 dev_warn(uhci_dev(uhci), "td %p still in list!\n", td);
  64         if (!list_empty(&td->remove_list))
  65                 dev_warn(uhci_dev(uhci), "td %p still in remove_list!\n", td);
  66         if (!list_empty(&td->fl_list))
  67                 dev_warn(uhci_dev(uhci), "td %p still in fl_list!\n", td);
  68
  69         dma_pool_free(uhci->td_pool, td, td->dma_handle);
  70 }
  71
  72 static inline void uhci_fill_td(struct uhci_td *td, u32 status,
  73                 u32 token, u32 buffer)
  74 {
  75         td->status = cpu_to_le32(status);
  76         td->token = cpu_to_le32(token);
  77         td->buffer = cpu_to_le32(buffer);
  78 }
  79
  80 /*
  81  * We insert Isochronous URBs directly into the frame list at the beginning
  82  */
  83 static inline void uhci_insert_td_in_frame_list(struct uhci_hcd *uhci,
  84                 struct uhci_td *td, unsigned framenum)
  85 {
  86         framenum &= (UHCI_NUMFRAMES - 1);
  87
  88         td->frame = framenum;
  89
  90         /* Is there a TD already mapped there? */
  91         if (uhci->frame_cpu[framenum]) {
  92                 struct uhci_td *ftd, *ltd;
  93
  94                 ftd = uhci->frame_cpu[framenum];
  95                 ltd = list_entry(ftd->fl_list.prev, struct uhci_td, fl_list);
  96
  97                 list_add_tail(&td->fl_list, &ftd->fl_list);
  98
  99                 td->link = ltd->link;
 100                 wmb();
 101                 ltd->link = cpu_to_le32(td->dma_handle);
 102         } else {
 103                 td->link = uhci->frame[framenum];
 104                 wmb();
 105                 uhci->frame[framenum] = cpu_to_le32(td->dma_handle);
 106                 uhci->frame_cpu[framenum] = td;
 107         }
 108 }
 109
 110 static inline void uhci_remove_td_from_frame_list(struct uhci_hcd *uhci,
 111                 struct uhci_td *td)
 112 {
 113         /* If it's not inserted, don't remove it */
 114         if (td->frame == -1) {
 115                 WARN_ON(!list_empty(&td->fl_list));
 116                 return;
 117         }
 118
 119         if (uhci->frame_cpu[td->frame] == td) {
 120                 if (list_empty(&td->fl_list)) {
 121                         uhci->frame[td->frame] = td->link;
 122                         uhci->frame_cpu[td->frame] = NULL;
 123                 } else {
 124                         struct uhci_td *ntd;
 125
 126                         ntd = list_entry(td->fl_list.next, struct uhci_td, fl_list);
 127                         uhci->frame[td->frame] = cpu_to_le32(ntd->dma_handle);
 128                         uhci->frame_cpu[td->frame] = ntd;
 129                 }
 130         } else {
 131                 struct uhci_td *ptd;
 132
 133                 ptd = list_entry(td->fl_list.prev, struct uhci_td, fl_list);
 134                 ptd->link = td->link;
 135         }
 136
 137         list_del_init(&td->fl_list);
 138         td->frame = -1;
 139 }
 140
 141 /*
 142  * Remove all the TDs for an Isochronous URB from the frame list
 143  */
 144 static void uhci_unlink_isochronous_tds(struct uhci_hcd *uhci, struct urb *urb)
 145 {
 146         struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
 147         struct uhci_td *td;
 148
 149         list_for_each_entry(td, &urbp->td_list, list)
 150                 uhci_remove_td_from_frame_list(uhci, td);
 151         wmb();
 152 }
 153
 154 static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci,
 155                 struct usb_device *udev, struct usb_host_endpoint *hep)
 156 {
 157         dma_addr_t dma_handle;
 158         struct uhci_qh *qh;
 159
 160         qh = dma_pool_alloc(uhci->qh_pool, GFP_ATOMIC, &dma_handle);
 161         if (!qh)
 162                 return NULL;
 163
 164         qh->dma_handle = dma_handle;
 165
 166         qh->element = UHCI_PTR_TERM;
 167         qh->link = UHCI_PTR_TERM;
 168
 169         INIT_LIST_HEAD(&qh->queue);
 170         INIT_LIST_HEAD(&qh->node);
 171
 172         if (udev) {             /* Normal QH */
 173                 qh->dummy_td = uhci_alloc_td(uhci);
 174                 if (!qh->dummy_td) {
 175                         dma_pool_free(uhci->qh_pool, qh, dma_handle);
 176                         return NULL;
 177                 }
 178                 qh->state = QH_STATE_IDLE;
 179                 qh->hep = hep;
 180                 qh->udev = udev;
 181                 hep->hcpriv = qh;
 182                 qh->type = hep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
 183
 184         } else {                /* Skeleton QH */
 185                 qh->state = QH_STATE_ACTIVE;
 186                 qh->udev = NULL;
 187                 qh->type = -1;
 188         }
 189         return qh;
 190 }
 191
 192 static void uhci_free_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 193 {
 194         WARN_ON(qh->state != QH_STATE_IDLE && qh->udev);
 195         if (!list_empty(&qh->queue))
 196                 dev_warn(uhci_dev(uhci), "qh %p list not empty!\n", qh);
 197
 198         list_del(&qh->node);
 199         if (qh->udev) {
 200                 qh->hep->hcpriv = NULL;
 201                 uhci_free_td(uhci, qh->dummy_td);
 202         }
 203         dma_pool_free(uhci->qh_pool, qh, qh->dma_handle);
 204 }
 205
 206 /*
 207  * When the currently executing URB is dequeued, save its current toggle value
 208  */
 209 static void uhci_save_toggle(struct uhci_qh *qh, struct urb *urb)
 210 {
 211         struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
 212         struct uhci_td *td;
 213
 214         /* If the QH element pointer is UHCI_PTR_TERM then then currently
 215          * executing URB has already been unlinked, so this one isn't it. */
 216         if (qh_element(qh) == UHCI_PTR_TERM ||
 217                                 qh->queue.next != &urbp->node)
 218                 return;
 219         qh->element = UHCI_PTR_TERM;
 220
 221         /* Only bulk and interrupt pipes have to worry about toggles */
 222         if (!(qh->type == USB_ENDPOINT_XFER_BULK ||
 223                         qh->type == USB_ENDPOINT_XFER_INT))
 224                 return;
 225
 226         /* Find the first active TD; that's the device's toggle state */
 227         list_for_each_entry(td, &urbp->td_list, list) {
 228                 if (td_status(td) & TD_CTRL_ACTIVE) {
 229                         qh->needs_fixup = 1;
 230                         qh->initial_toggle = uhci_toggle(td_token(td));
 231                         return;
 232                 }
 233         }
 234
 235         WARN_ON(1);
 236 }
 237
 238 /*
 239  * Fix up the data toggles for URBs in a queue, when one of them
 240  * terminates early (short transfer, error, or dequeued).
 241  */
 242 static void uhci_fixup_toggles(struct uhci_qh *qh, int skip_first)
 243 {
 244         struct urb_priv *urbp = NULL;
 245         struct uhci_td *td;
 246         unsigned int toggle = qh->initial_toggle;
 247         unsigned int pipe;
 248
 249         /* Fixups for a short transfer start with the second URB in the
 250          * queue (the short URB is the first). */
 251         if (skip_first)
 252                 urbp = list_entry(qh->queue.next, struct urb_priv, node);
 253
 254         /* When starting with the first URB, if the QH element pointer is
 255          * still valid then we know the URB's toggles are okay. */
 256         else if (qh_element(qh) != UHCI_PTR_TERM)
 257                 toggle = 2;
 258
 259         /* Fix up the toggle for the URBs in the queue.  Normally this
 260          * loop won't run more than once: When an error or short transfer
 261          * occurs, the queue usually gets emptied. */
 262         urbp = list_prepare_entry(urbp, &qh->queue, node);
 263         list_for_each_entry_continue(urbp, &qh->queue, node) {
 264
 265                 /* If the first TD has the right toggle value, we don't
 266                  * need to change any toggles in this URB */
 267                 td = list_entry(urbp->td_list.next, struct uhci_td, list);
 268                 if (toggle > 1 || uhci_toggle(td_token(td)) == toggle) {
 269                         td = list_entry(urbp->td_list.next, struct uhci_td,
 270                                         list);
 271                         toggle = uhci_toggle(td_token(td)) ^ 1;
 272
 273                 /* Otherwise all the toggles in the URB have to be switched */
 274                 } else {
 275                         list_for_each_entry(td, &urbp->td_list, list) {
 276                                 td->token ^= __constant_cpu_to_le32(
 277                                                         TD_TOKEN_TOGGLE);
 278                                 toggle ^= 1;
 279                         }
 280                 }
 281         }
 282
 283         wmb();
 284         pipe = list_entry(qh->queue.next, struct urb_priv, node)->urb->pipe;
 285         usb_settoggle(qh->udev, usb_pipeendpoint(pipe),
 286                         usb_pipeout(pipe), toggle);
 287         qh->needs_fixup = 0;
 288 }
 289
 290 /*
 291  * Put a QH on the schedule in both hardware and software
 292  */
 293 static void uhci_activate_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 294 {
 295         struct uhci_qh *pqh;
 296
 297         WARN_ON(list_empty(&qh->queue));
 298
 299         /* Set the element pointer if it isn't set already.
 300          * This isn't needed for Isochronous queues, but it doesn't hurt. */
 301         if (qh_element(qh) == UHCI_PTR_TERM) {
 302                 struct urb_priv *urbp = list_entry(qh->queue.next,
 303                                 struct urb_priv, node);
 304                 struct uhci_td *td = list_entry(urbp->td_list.next,
 305                                 struct uhci_td, list);
 306
 307                 qh->element = cpu_to_le32(td->dma_handle);
 308         }
 309
 310         if (qh->state == QH_STATE_ACTIVE)
 311                 return;
 312         qh->state = QH_STATE_ACTIVE;
 313
 314         /* Move the QH from its old list to the end of the appropriate
 315          * skeleton's list */
 316         if (qh == uhci->next_qh)
 317                 uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
 318                                 node);
 319         list_move_tail(&qh->node, &qh->skel->node);
 320
 321         /* Link it into the schedule */
 322         pqh = list_entry(qh->node.prev, struct uhci_qh, node);
 323         qh->link = pqh->link;
 324         wmb();
 325         pqh->link = UHCI_PTR_QH | cpu_to_le32(qh->dma_handle);
 326 }
 327
 328 /*
 329  * Take a QH off the hardware schedule
 330  */
 331 static void uhci_unlink_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 332 {
 333         struct uhci_qh *pqh;
 334
 335         if (qh->state == QH_STATE_UNLINKING)
 336                 return;
 337         WARN_ON(qh->state != QH_STATE_ACTIVE || !qh->udev);
 338         qh->state = QH_STATE_UNLINKING;
 339
 340         /* Unlink the QH from the schedule and record when we did it */
 341         pqh = list_entry(qh->node.prev, struct uhci_qh, node);
 342         pqh->link = qh->link;
 343         mb();
 344
 345         uhci_get_current_frame_number(uhci);
 346         qh->unlink_frame = uhci->frame_number;
 347
 348         /* Force an interrupt so we know when the QH is fully unlinked */
 349         if (list_empty(&uhci->skel_unlink_qh->node))
 350                 uhci_set_next_interrupt(uhci);
 351
 352         /* Move the QH from its old list to the end of the unlinking list */
 353         if (qh == uhci->next_qh)
 354                 uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
 355                                 node);
 356         list_move_tail(&qh->node, &uhci->skel_unlink_qh->node);
 357 }
 358
 359 /*
 360  * When we and the controller are through with a QH, it becomes IDLE.
 361  * This happens when a QH has been off the schedule (on the unlinking
 362  * list) for more than one frame, or when an error occurs while adding
 363  * the first URB onto a new QH.
 364  */
 365 static void uhci_make_qh_idle(struct uhci_hcd *uhci, struct uhci_qh *qh)
 366 {
 367         WARN_ON(qh->state == QH_STATE_ACTIVE);
 368
 369         if (qh == uhci->next_qh)
 370                 uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
 371                                 node);
 372         list_move(&qh->node, &uhci->idle_qh_list);
 373         qh->state = QH_STATE_IDLE;
 374
 375         /* If anyone is waiting for a QH to become idle, wake them up */
 376         if (uhci->num_waiting)
 377                 wake_up_all(&uhci->waitqh);
 378 }
 379
 380 static inline struct urb_priv *uhci_alloc_urb_priv(struct uhci_hcd *uhci,
 381                 struct urb *urb)
 382 {
 383         struct urb_priv *urbp;
 384
 385         urbp = kmem_cache_alloc(uhci_up_cachep, SLAB_ATOMIC);
 386         if (!urbp)
 387                 return NULL;
 388
 389         memset((void *)urbp, 0, sizeof(*urbp));
 390
 391         urbp->urb = urb;
 392         urb->hcpriv = urbp;
 393
 394         INIT_LIST_HEAD(&urbp->node);
 395         INIT_LIST_HEAD(&urbp->td_list);
 396
 397         return urbp;
 398 }
 399
 400 static void uhci_add_td_to_urb(struct urb *urb, struct uhci_td *td)
 401 {
 402         struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
 403
 404         list_add_tail(&td->list, &urbp->td_list);
 405 }
 406
 407 static void uhci_remove_td_from_urb(struct uhci_td *td)
 408 {
 409         if (list_empty(&td->list))
 410                 return;
 411
 412         list_del_init(&td->list);
 413 }
 414
 415 static void uhci_free_urb_priv(struct uhci_hcd *uhci,
 416                 struct urb_priv *urbp)
 417 {
 418         struct uhci_td *td, *tmp;
 419
 420         if (!list_empty(&urbp->node))
 421                 dev_warn(uhci_dev(uhci), "urb %p still on QH's list!\n",
 422                                 urbp->urb);
 423
 424         uhci_get_current_frame_number(uhci);
 425         if (uhci->frame_number + uhci->is_stopped != uhci->td_remove_age) {
 426                 uhci_free_pending_tds(uhci);
 427                 uhci->td_remove_age = uhci->frame_number;
 428         }
 429
 430         /* Check to see if the remove list is empty. Set the IOC bit */
 431         /* to force an interrupt so we can remove the TDs. */
 432         if (list_empty(&uhci->td_remove_list))
 433                 uhci_set_next_interrupt(uhci);
 434
 435         list_for_each_entry_safe(td, tmp, &urbp->td_list, list) {
 436                 uhci_remove_td_from_urb(td);
 437                 list_add(&td->remove_list, &uhci->td_remove_list);
 438         }
 439
 440         urbp->urb->hcpriv = NULL;
 441         kmem_cache_free(uhci_up_cachep, urbp);
 442 }
 443
 444 static void uhci_inc_fsbr(struct uhci_hcd *uhci, struct urb *urb)
 445 {
 446         struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
 447
 448         if ((!(urb->transfer_flags & URB_NO_FSBR)) && !urbp->fsbr) {
 449                 urbp->fsbr = 1;
 450                 if (!uhci->fsbr++ && !uhci->fsbrtimeout)
 451                         uhci->skel_term_qh->link = cpu_to_le32(uhci->skel_fs_control_qh->dma_handle) | UHCI_PTR_QH;
 452         }
 453 }
 454
 455 static void uhci_dec_fsbr(struct uhci_hcd *uhci, struct urb *urb)
 456 {
 457         struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
 458
 459         if ((!(urb->transfer_flags & URB_NO_FSBR)) && urbp->fsbr) {
 460                 urbp->fsbr = 0;
 461                 if (!--uhci->fsbr)
 462                         uhci->fsbrtimeout = jiffies + FSBR_DELAY;
 463         }
 464 }
 465
 466 /*
 467  * Map status to standard result codes
 468  *
 469  * <status> is (td_status(td) & 0xF60000), a.k.a.
 470  * uhci_status_bits(td_status(td)).
 471  * Note: <status> does not include the TD_CTRL_NAK bit.
 472  * <dir_out> is True for output TDs and False for input TDs.
 473  */
 474 static int uhci_map_status(int status, int dir_out)
 475 {
 476         if (!status)
 477                 return 0;
 478         if (status & TD_CTRL_BITSTUFF)                  /* Bitstuff error */
 479                 return -EPROTO;
 480         if (status & TD_CTRL_CRCTIMEO) {                /* CRC/Timeout */
 481                 if (dir_out)
 482                         return -EPROTO;
 483                 else
 484                         return -EILSEQ;
 485         }
 486         if (status & TD_CTRL_BABBLE)                    /* Babble */
 487                 return -EOVERFLOW;
 488         if (status & TD_CTRL_DBUFERR)                   /* Buffer error */
 489                 return -ENOSR;
 490         if (status & TD_CTRL_STALLED)                   /* Stalled */
 491                 return -EPIPE;
 492         WARN_ON(status & TD_CTRL_ACTIVE);               /* Active */
 493         return 0;
 494 }
 495
 496 /*
 497  * Control transfers
 498  */
 499 static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
 500                 struct uhci_qh *qh)
 501 {
 502         struct uhci_td *td;
 503         unsigned long destination, status;
 504         int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize);
 505         int len = urb->transfer_buffer_length;
 506         dma_addr_t data = urb->transfer_dma;
 507         __le32 *plink;
 508
 509         /* The "pipe" thing contains the destination in bits 8--18 */
 510         destination = (urb->pipe & PIPE_DEVEP_MASK) | USB_PID_SETUP;
 511
 512         /* 3 errors, dummy TD remains inactive */
 513         status = uhci_maxerr(3);
 514         if (urb->dev->speed == USB_SPEED_LOW)
 515                 status |= TD_CTRL_LS;
 516
 517         /*
 518          * Build the TD for the control request setup packet
 519          */
 520         td = qh->dummy_td;
 521         uhci_add_td_to_urb(urb, td);
 522         uhci_fill_td(td, status, destination | uhci_explen(8),
 523                         urb->setup_dma);
 524         plink = &td->link;
 525         status |= TD_CTRL_ACTIVE;
 526
 527         /*
 528          * If direction is "send", change the packet ID from SETUP (0x2D)
 529          * to OUT (0xE1).  Else change it from SETUP to IN (0x69) and
 530          * set Short Packet Detect (SPD) for all data packets.
 531          */
 532         if (usb_pipeout(urb->pipe))
 533                 destination ^= (USB_PID_SETUP ^ USB_PID_OUT);
 534         else {
 535                 destination ^= (USB_PID_SETUP ^ USB_PID_IN);
 536                 status |= TD_CTRL_SPD;
 537         }
 538
 539         /*
 540          * Build the DATA TDs
 541          */
 542         while (len > 0) {
 543                 int pktsze = min(len, maxsze);
 544
 545                 td = uhci_alloc_td(uhci);
 546                 if (!td)
 547                         goto nomem;
 548                 *plink = cpu_to_le32(td->dma_handle);
 549
 550                 /* Alternate Data0/1 (start with Data1) */
 551                 destination ^= TD_TOKEN_TOGGLE;
 552
 553                 uhci_add_td_to_urb(urb, td);
 554                 uhci_fill_td(td, status, destination | uhci_explen(pktsze),
 555                                 data);
 556                 plink = &td->link;
 557
 558                 data += pktsze;
 559                 len -= pktsze;
 560         }
 561
 562         /*
 563          * Build the final TD for control status
 564          */
 565         td = uhci_alloc_td(uhci);
 566         if (!td)
 567                 goto nomem;
 568         *plink = cpu_to_le32(td->dma_handle);
 569
 570         /*
 571          * It's IN if the pipe is an output pipe or we're not expecting
 572          * data back.
 573          */
 574         destination &= ~TD_TOKEN_PID_MASK;
 575         if (usb_pipeout(urb->pipe) || !urb->transfer_buffer_length)
 576                 destination |= USB_PID_IN;
 577         else
 578                 destination |= USB_PID_OUT;
 579
 580         destination |= TD_TOKEN_TOGGLE;         /* End in Data1 */
 581
 582         status &= ~TD_CTRL_SPD;
 583
 584         uhci_add_td_to_urb(urb, td);
 585         uhci_fill_td(td, status | TD_CTRL_IOC,
 586                         destination | uhci_explen(0), 0);
 587         plink = &td->link;
 588
 589         /*
 590          * Build the new dummy TD and activate the old one
 591          */
 592         td = uhci_alloc_td(uhci);
 593         if (!td)
 594                 goto nomem;
 595         *plink = cpu_to_le32(td->dma_handle);
 596
 597         uhci_fill_td(td, 0, USB_PID_OUT | uhci_explen(0), 0);
 598         wmb();
 599         qh->dummy_td->status |= __constant_cpu_to_le32(TD_CTRL_ACTIVE);
 600         qh->dummy_td = td;
 601
 602         /* Low-speed transfers get a different queue, and won't hog the bus.
 603          * Also, some devices enumerate better without FSBR; the easiest way
 604          * to do that is to put URBs on the low-speed queue while the device
 605          * isn't in the CONFIGURED state. */
 606         if (urb->dev->speed == USB_SPEED_LOW ||
 607                         urb->dev->state != USB_STATE_CONFIGURED)
 608                 qh->skel = uhci->skel_ls_control_qh;
 609         else {
 610                 qh->skel = uhci->skel_fs_control_qh;
 611                 uhci_inc_fsbr(uhci, urb);
 612         }
 613         return 0;
 614
 615 nomem:
 616         /* Remove the dummy TD from the td_list so it doesn't get freed */
 617         uhci_remove_td_from_urb(qh->dummy_td);
 618         return -ENOMEM;
 619 }
 620
 621 /*
 622  * If control-IN transfer was short, the status packet wasn't sent.
 623  * This routine changes the element pointer in the QH to point at the
 624  * status TD.  It's safe to do this even while the QH is live, because
 625  * the hardware only updates the element pointer following a successful
 626  * transfer.  The inactive TD for the short packet won't cause an update,
 627  * so the pointer won't get overwritten.  The next time the controller
 628  * sees this QH, it will send the status packet.
 629  */
 630 static int usb_control_retrigger_status(struct uhci_hcd *uhci, struct urb *urb)
 631 {
 632         struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
 633         struct uhci_td *td;
 634
 635         urbp->short_transfer = 1;
 636
 637         td = list_entry(urbp->td_list.prev, struct uhci_td, list);
 638         urbp->qh->element = cpu_to_le32(td->dma_handle);
 639
 640         return -EINPROGRESS;
 641 }
 642
 643
 644 static int uhci_result_control(struct uhci_hcd *uhci, struct urb *urb)
 645 {
 646         struct list_head *tmp, *head;
 647         struct urb_priv *urbp = urb->hcpriv;
 648         struct uhci_td *td;
 649         unsigned int status;
 650         int ret = 0;
 651
 652         head = &urbp->td_list;
 653         if (urbp->short_transfer) {
 654                 tmp = head->prev;
 655                 goto status_stage;
 656         }
 657
 658         urb->actual_length = 0;
 659
 660         tmp = head->next;
 661         td = list_entry(tmp, struct uhci_td, list);
 662
 663         /* The first TD is the SETUP stage, check the status, but skip */
 664         /*  the count */
 665         status = uhci_status_bits(td_status(td));
 666         if (status & TD_CTRL_ACTIVE)
 667                 return -EINPROGRESS;
 668
 669         if (status)
 670                 goto td_error;
 671
 672         /* The rest of the TDs (but the last) are data */
 673         tmp = tmp->next;
 674         while (tmp != head && tmp->next != head) {
 675                 unsigned int ctrlstat;
 676
 677                 td = list_entry(tmp, struct uhci_td, list);
 678                 tmp = tmp->next;
 679
 680                 ctrlstat = td_status(td);
 681                 status = uhci_status_bits(ctrlstat);
 682                 if (status & TD_CTRL_ACTIVE)
 683                         return -EINPROGRESS;
 684
 685                 urb->actual_length += uhci_actual_length(ctrlstat);
 686
 687                 if (status)
 688                         goto td_error;
 689
 690                 /* Check to see if we received a short packet */
 691                 if (uhci_actual_length(ctrlstat) <
 692                                 uhci_expected_length(td_token(td))) {
 693                         if (urb->transfer_flags & URB_SHORT_NOT_OK) {
 694                                 ret = -EREMOTEIO;
 695                                 goto err;
 696                         }
 697
 698                         return usb_control_retrigger_status(uhci, urb);
 699                 }
 700         }
 701
 702 status_stage:
 703         td = list_entry(tmp, struct uhci_td, list);
 704
 705         /* Control status stage */
 706         status = td_status(td);
 707
 708 #ifdef I_HAVE_BUGGY_APC_BACKUPS
 709         /* APC BackUPS Pro kludge */
 710         /* It tries to send all of the descriptor instead of the amount */
 711         /*  we requested */
 712         if (status & TD_CTRL_IOC &&     /* IOC is masked out by uhci_status_bits */
 713             status & TD_CTRL_ACTIVE &&
 714             status & TD_CTRL_NAK)
 715                 return 0;
 716 #endif
 717
 718         status = uhci_status_bits(status);
 719         if (status & TD_CTRL_ACTIVE)
 720                 return -EINPROGRESS;
 721
 722         if (status)
 723                 goto td_error;
 724
 725         return 0;
 726
 727 td_error:
 728         ret = uhci_map_status(status, uhci_packetout(td_token(td)));
 729
 730 err:
 731         if ((debug == 1 && ret != -EPIPE) || debug > 1) {
 732                 /* Some debugging code */
 733                 dev_dbg(uhci_dev(uhci), "%s: failed with status %x\n",
 734                                 __FUNCTION__, status);
 735
 736                 if (errbuf) {
 737                         /* Print the chain for debugging purposes */
 738                         uhci_show_qh(urbp->qh, errbuf, ERRBUF_LEN, 0);
 739                         lprintk(errbuf);
 740                 }
 741         }
 742
 743         /* Note that the queue has stopped */
 744         urbp->qh->element = UHCI_PTR_TERM;
 745         urbp->qh->is_stopped = 1;
 746         return ret;
 747 }
 748
 749 /*
 750  * Common submit for bulk and interrupt
 751  */
 752 static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb,
 753                 struct uhci_qh *qh)
 754 {
 755         struct uhci_td *td;
 756         unsigned long destination, status;
 757         int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize);
 758         int len = urb->transfer_buffer_length;
 759         dma_addr_t data = urb->transfer_dma;
 760         __le32 *plink;
 761         unsigned int toggle;
 762
 763         if (len < 0)
 764                 return -EINVAL;
 765
 766         /* The "pipe" thing contains the destination in bits 8--18 */
 767         destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
 768         toggle = usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
 769                          usb_pipeout(urb->pipe));
 770
 771         /* 3 errors, dummy TD remains inactive */
 772         status = uhci_maxerr(3);
 773         if (urb->dev->speed == USB_SPEED_LOW)
 774                 status |= TD_CTRL_LS;
 775         if (usb_pipein(urb->pipe))
 776                 status |= TD_CTRL_SPD;
 777
 778         /*
 779          * Build the DATA TDs
 780          */
 781         plink = NULL;
 782         td = qh->dummy_td;
 783         do {    /* Allow zero length packets */
 784                 int pktsze = maxsze;
 785
 786                 if (len <= pktsze) {            /* The last packet */
 787                         pktsze = len;
 788                         if (!(urb->transfer_flags & URB_SHORT_NOT_OK))
 789                                 status &= ~TD_CTRL_SPD;
 790                 }
 791
 792                 if (plink) {
 793                         td = uhci_alloc_td(uhci);
 794                         if (!td)
 795                                 goto nomem;
 796                         *plink = cpu_to_le32(td->dma_handle);
 797                 }
 798                 uhci_add_td_to_urb(urb, td);
 799                 uhci_fill_td(td, status,
 800                                 destination | uhci_explen(pktsze) |
 801                                         (toggle << TD_TOKEN_TOGGLE_SHIFT),
 802                                 data);
 803                 plink = &td->link;
 804                 status |= TD_CTRL_ACTIVE;
 805
 806                 data += pktsze;
 807                 len -= maxsze;
 808                 toggle ^= 1;
 809         } while (len > 0);
 810
 811         /*
 812          * URB_ZERO_PACKET means adding a 0-length packet, if direction
 813          * is OUT and the transfer_length was an exact multiple of maxsze,
 814          * hence (len = transfer_length - N * maxsze) == 0
 815          * however, if transfer_length == 0, the zero packet was already
 816          * prepared above.
 817          */
 818         if ((urb->transfer_flags & URB_ZERO_PACKET) &&
 819                         usb_pipeout(urb->pipe) && len == 0 &&
 820                         urb->transfer_buffer_length > 0) {
 821                 td = uhci_alloc_td(uhci);
 822                 if (!td)
 823                         goto nomem;
 824                 *plink = cpu_to_le32(td->dma_handle);
 825
 826                 uhci_add_td_to_urb(urb, td);
 827                 uhci_fill_td(td, status,
 828                                 destination | uhci_explen(0) |
 829                                         (toggle << TD_TOKEN_TOGGLE_SHIFT),
 830                                 data);
 831                 plink = &td->link;
 832
 833                 toggle ^= 1;
 834         }
 835
 836         /* Set the interrupt-on-completion flag on the last packet.
 837          * A more-or-less typical 4 KB URB (= size of one memory page)
 838          * will require about 3 ms to transfer; that's a little on the
 839          * fast side but not enough to justify delaying an interrupt
 840          * more than 2 or 3 URBs, so we will ignore the URB_NO_INTERRUPT
 841          * flag setting. */
 842         td->status |= __constant_cpu_to_le32(TD_CTRL_IOC);
 843
 844         /*
 845          * Build the new dummy TD and activate the old one
 846          */
 847         td = uhci_alloc_td(uhci);
 848         if (!td)
 849                 goto nomem;
 850         *plink = cpu_to_le32(td->dma_handle);
 851
 852         uhci_fill_td(td, 0, USB_PID_OUT | uhci_explen(0), 0);
 853         wmb();
 854         qh->dummy_td->status |= __constant_cpu_to_le32(TD_CTRL_ACTIVE);
 855         qh->dummy_td = td;
 856
 857         usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
 858                         usb_pipeout(urb->pipe), toggle);
 859         return 0;
 860
 861 nomem:
 862         /* Remove the dummy TD from the td_list so it doesn't get freed */
 863         uhci_remove_td_from_urb(qh->dummy_td);
 864         return -ENOMEM;
 865 }
 866
 867 /*
 868  * Common result for bulk and interrupt
 869  */
 870 static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
 871 {
 872         struct urb_priv *urbp = urb->hcpriv;
 873         struct uhci_td *td;
 874         unsigned int status = 0;
 875         int ret = 0;
 876
 877         urb->actual_length = 0;
 878
 879         list_for_each_entry(td, &urbp->td_list, list) {
 880                 unsigned int ctrlstat = td_status(td);
 881
 882                 status = uhci_status_bits(ctrlstat);
 883                 if (status & TD_CTRL_ACTIVE)
 884                         return -EINPROGRESS;
 885
 886                 urb->actual_length += uhci_actual_length(ctrlstat);
 887
 888                 if (status)
 889                         goto td_error;
 890
 891                 if (uhci_actual_length(ctrlstat) <
 892                                 uhci_expected_length(td_token(td))) {
 893                         if (urb->transfer_flags & URB_SHORT_NOT_OK) {
 894                                 ret = -EREMOTEIO;
 895                                 goto err;
 896                         }
 897
 898                         /*
 899                          * This URB stopped short of its end.  We have to
 900                          * fix up the toggles of the following URBs on the
 901                          * queue and restart the queue.
 902                          *
 903                          * Do this only the first time we encounter the
 904                          * short URB.
 905                          */
 906                         if (!urbp->short_transfer) {
 907                                 urbp->short_transfer = 1;
 908                                 urbp->qh->initial_toggle =
 909                                                 uhci_toggle(td_token(td)) ^ 1;
 910                                 uhci_fixup_toggles(urbp->qh, 1);
 911
 912                                 td = list_entry(urbp->td_list.prev,
 913                                                 struct uhci_td, list);
 914                                 urbp->qh->element = td->link;
 915                         }
 916                         break;
 917                 }
 918         }
 919
 920         return 0;
 921
 922 td_error:
 923         ret = uhci_map_status(status, uhci_packetout(td_token(td)));
 924
 925         if ((debug == 1 && ret != -EPIPE) || debug > 1) {
 926                 /* Some debugging code */
 927                 dev_dbg(uhci_dev(uhci), "%s: failed with status %x\n",
 928                                 __FUNCTION__, status);
 929
 930                 if (debug > 1 && errbuf) {
 931                         /* Print the chain for debugging purposes */
 932                         uhci_show_qh(urbp->qh, errbuf, ERRBUF_LEN, 0);
 933                         lprintk(errbuf);
 934                 }
 935         }
 936 err:
 937
 938         /* Note that the queue has stopped and save the next toggle value */
 939         urbp->qh->element = UHCI_PTR_TERM;
 940         urbp->qh->is_stopped = 1;
 941         urbp->qh->needs_fixup = 1;
 942         urbp->qh->initial_toggle = uhci_toggle(td_token(td)) ^
 943                         (ret == -EREMOTEIO);
 944         return ret;
 945 }
 946
 947 static inline int uhci_submit_bulk(struct uhci_hcd *uhci, struct urb *urb,
 948                 struct uhci_qh *qh)
 949 {
 950         int ret;
 951
 952         /* Can't have low-speed bulk transfers */
 953         if (urb->dev->speed == USB_SPEED_LOW)
 954                 return -EINVAL;
 955
 956         qh->skel = uhci->skel_bulk_qh;
 957         ret = uhci_submit_common(uhci, urb, qh);
 958         if (ret == 0)
 959                 uhci_inc_fsbr(uhci, urb);
 960         return ret;
 961 }
 962
 963 static inline int uhci_submit_interrupt(struct uhci_hcd *uhci, struct urb *urb,
 964                 struct uhci_qh *qh)
 965 {
 966         /* USB 1.1 interrupt transfers only involve one packet per interval.
 967          * Drivers can submit URBs of any length, but longer ones will need
 968          * multiple intervals to complete.
 969          */
 970         qh->skel = uhci->skelqh[__interval_to_skel(urb->interval)];
 971         return uhci_submit_common(uhci, urb, qh);
 972 }
 973
 974 /*
 975  * Isochronous transfers
 976  */
 977 static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb,
 978                 struct uhci_qh *qh)
 979 {
 980         struct uhci_td *td = NULL;      /* Since urb->number_of_packets > 0 */
 981         int i, frame;
 982         unsigned long destination, status;
 983         struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
 984
 985         if (urb->number_of_packets > 900)       /* 900? Why? */
 986                 return -EFBIG;
 987
 988         status = TD_CTRL_ACTIVE | TD_CTRL_IOS;
 989         destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
 990
 991         /* Figure out the starting frame number */
 992         if (urb->transfer_flags & URB_ISO_ASAP) {
 993                 if (list_empty(&qh->queue)) {
 994                         uhci_get_current_frame_number(uhci);
 995                         urb->start_frame = (uhci->frame_number + 10);
 996
 997                 } else {                /* Go right after the last one */
 998                         struct urb *last_urb;
 999
1000                         last_urb = list_entry(qh->queue.prev,
1001                                         struct urb_priv, node)->urb;
1002                         urb->start_frame = (last_urb->start_frame +
1003                                         last_urb->number_of_packets *
1004                                         last_urb->interval);
1005                 }
1006         } else {
1007                 /* FIXME: Sanity check */
1008         }
1009         urb->start_frame &= (UHCI_NUMFRAMES - 1);
1010
1011         for (i = 0; i < urb->number_of_packets; i++) {
1012                 td = uhci_alloc_td(uhci);
1013                 if (!td)
1014                         return -ENOMEM;
1015
1016                 uhci_add_td_to_urb(urb, td);
1017                 uhci_fill_td(td, status, destination |
1018                                 uhci_explen(urb->iso_frame_desc[i].length),
1019                                 urb->transfer_dma +
1020                                         urb->iso_frame_desc[i].offset);
1021         }
1022
1023         /* Set the interrupt-on-completion flag on the last packet. */
1024         td->status |= __constant_cpu_to_le32(TD_CTRL_IOC);
1025
1026         qh->skel = uhci->skel_iso_qh;
1027
1028         /* Add the TDs to the frame list */
1029         frame = urb->start_frame;
1030         list_for_each_entry(td, &urbp->td_list, list) {
1031                 uhci_insert_td_in_frame_list(uhci, td, frame);
1032                 frame += urb->interval;
1033         }
1034
1035         return 0;
1036 }
1037
1038 static int uhci_result_isochronous(struct uhci_hcd *uhci, struct urb *urb)
1039 {
1040         struct uhci_td *td;
1041         struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
1042         int status;
1043         int i, ret = 0;
1044
1045         urb->actual_length = urb->error_count = 0;
1046
1047         i = 0;
1048         list_for_each_entry(td, &urbp->td_list, list) {
1049                 int actlength;
1050                 unsigned int ctrlstat = td_status(td);
1051
1052                 if (ctrlstat & TD_CTRL_ACTIVE)
1053                         return -EINPROGRESS;
1054
1055                 actlength = uhci_actual_length(ctrlstat);
1056                 urb->iso_frame_desc[i].actual_length = actlength;
1057                 urb->actual_length += actlength;
1058
1059                 status = uhci_map_status(uhci_status_bits(ctrlstat),
1060                                 usb_pipeout(urb->pipe));
1061                 urb->iso_frame_desc[i].status = status;
1062                 if (status) {
1063                         urb->error_count++;
1064                         ret = status;
1065                 }
1066
1067                 i++;
1068         }
1069
1070         return ret;
1071 }
1072
1073 static int uhci_urb_enqueue(struct usb_hcd *hcd,
1074                 struct usb_host_endpoint *hep,
1075                 struct urb *urb, gfp_t mem_flags)
1076 {
1077         int ret;
1078         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
1079         unsigned long flags;
1080         struct urb_priv *urbp;
1081         struct uhci_qh *qh;
1082         int bustime;
1083
1084         spin_lock_irqsave(&uhci->lock, flags);
1085
1086         ret = urb->status;
1087         if (ret != -EINPROGRESS)                /* URB already unlinked! */
1088                 goto done;
1089
1090         ret = -ENOMEM;
1091         urbp = uhci_alloc_urb_priv(uhci, urb);
1092         if (!urbp)
1093                 goto done;
1094
1095         if (hep->hcpriv)
1096                 qh = (struct uhci_qh *) hep->hcpriv;
1097         else {
1098                 qh = uhci_alloc_qh(uhci, urb->dev, hep);
1099                 if (!qh)
1100                         goto err_no_qh;
1101         }
1102         urbp->qh = qh;
1103
1104         switch (qh->type) {
1105         case USB_ENDPOINT_XFER_CONTROL:
1106                 ret = uhci_submit_control(uhci, urb, qh);
1107                 break;
1108         case USB_ENDPOINT_XFER_BULK:
1109                 ret = uhci_submit_bulk(uhci, urb, qh);
1110                 break;
1111         case USB_ENDPOINT_XFER_INT:
1112                 if (list_empty(&qh->queue)) {
1113                         bustime = usb_check_bandwidth(urb->dev, urb);
1114                         if (bustime < 0)
1115                                 ret = bustime;
1116                         else {
1117                                 ret = uhci_submit_interrupt(uhci, urb, qh);
1118                                 if (ret == 0)
1119                                         usb_claim_bandwidth(urb->dev, urb, bustime, 0);
1120                         }
1121                 } else {        /* inherit from parent */
1122                         struct urb_priv *eurbp;
1123
1124                         eurbp = list_entry(qh->queue.prev, struct urb_priv,
1125                                         node);
1126                         urb->bandwidth = eurbp->urb->bandwidth;
1127                         ret = uhci_submit_interrupt(uhci, urb, qh);
1128                 }
1129                 break;
1130         case USB_ENDPOINT_XFER_ISOC:
1131                 bustime = usb_check_bandwidth(urb->dev, urb);
1132                 if (bustime < 0) {
1133                         ret = bustime;
1134                         break;
1135                 }
1136
1137                 ret = uhci_submit_isochronous(uhci, urb, qh);
1138                 if (ret == 0)
1139                         usb_claim_bandwidth(urb->dev, urb, bustime, 1);
1140                 break;
1141         }
1142         if (ret != 0)
1143                 goto err_submit_failed;
1144
1145         /* Add this URB to the QH */
1146         urbp->qh = qh;
1147         list_add_tail(&urbp->node, &qh->queue);
1148
1149         /* If the new URB is the first and only one on this QH then either
1150          * the QH is new and idle or else it's unlinked and waiting to
1151          * become idle, so we can activate it right away.  But only if the
1152          * queue isn't stopped. */
1153         if (qh->queue.next == &urbp->node && !qh->is_stopped)
1154                 uhci_activate_qh(uhci, qh);
1155         goto done;
1156
1157 err_submit_failed:
1158         if (qh->state == QH_STATE_IDLE)
1159                 uhci_make_qh_idle(uhci, qh);    /* Reclaim unused QH */
1160
1161 err_no_qh:
1162         uhci_free_urb_priv(uhci, urbp);
1163
1164 done:
1165         spin_unlock_irqrestore(&uhci->lock, flags);
1166         return ret;
1167 }
1168
1169 static int uhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb)
1170 {
1171         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
1172         unsigned long flags;
1173         struct urb_priv *urbp;
1174
1175         spin_lock_irqsave(&uhci->lock, flags);
1176         urbp = urb->hcpriv;
1177         if (!urbp)                      /* URB was never linked! */
1178                 goto done;
1179
1180         /* Remove Isochronous TDs from the frame list ASAP */
1181         if (urbp->qh->type == USB_ENDPOINT_XFER_ISOC)
1182                 uhci_unlink_isochronous_tds(uhci, urb);
1183         uhci_unlink_qh(uhci, urbp->qh);
1184
1185 done:
1186         spin_unlock_irqrestore(&uhci->lock, flags);
1187         return 0;
1188 }
1189
1190 /*
1191  * Finish unlinking an URB and give it back
1192  */
1193 static void uhci_giveback_urb(struct uhci_hcd *uhci, struct uhci_qh *qh,
1194                 struct urb *urb, struct pt_regs *regs)
1195 __releases(uhci->lock)
1196 __acquires(uhci->lock)
1197 {
1198         struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
1199
1200         /* Isochronous TDs get unlinked directly from the frame list */
1201         if (qh->type == USB_ENDPOINT_XFER_ISOC)
1202                 uhci_unlink_isochronous_tds(uhci, urb);
1203
1204         /* If the URB isn't first on its queue, adjust the link pointer
1205          * of the last TD in the previous URB. */
1206         else if (qh->queue.next != &urbp->node) {
1207                 struct urb_priv *purbp;
1208                 struct uhci_td *ptd, *ltd;
1209
1210                 purbp = list_entry(urbp->node.prev, struct urb_priv, node);
1211                 ptd = list_entry(purbp->td_list.prev, struct uhci_td,
1212                                 list);
1213                 ltd = list_entry(urbp->td_list.prev, struct uhci_td,
1214                                 list);
1215                 ptd->link = ltd->link;
1216         }
1217
1218         /* Take the URB off the QH's queue.  If the queue is now empty,
1219          * this is a perfect time for a toggle fixup. */
1220         list_del_init(&urbp->node);
1221         if (list_empty(&qh->queue) && qh->needs_fixup) {
1222                 usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
1223                                 usb_pipeout(urb->pipe), qh->initial_toggle);
1224                 qh->needs_fixup = 0;
1225         }
1226
1227         uhci_dec_fsbr(uhci, urb);       /* Safe since it checks */
1228         uhci_free_urb_priv(uhci, urbp);
1229
1230         switch (qh->type) {
1231         case USB_ENDPOINT_XFER_ISOC:
1232                 /* Release bandwidth for Interrupt or Isoc. transfers */
1233                 if (urb->bandwidth)
1234                         usb_release_bandwidth(urb->dev, urb, 1);
1235                 break;
1236         case USB_ENDPOINT_XFER_INT:
1237                 /* Release bandwidth for Interrupt or Isoc. transfers */
1238                 /* Make sure we don't release if we have a queued URB */
1239                 if (list_empty(&qh->queue) && urb->bandwidth)
1240                         usb_release_bandwidth(urb->dev, urb, 0);
1241                 else
1242                         /* bandwidth was passed on to queued URB, */
1243                         /* so don't let usb_unlink_urb() release it */
1244                         urb->bandwidth = 0;
1245                 break;
1246         }
1247
1248         spin_unlock(&uhci->lock);
1249         usb_hcd_giveback_urb(uhci_to_hcd(uhci), urb, regs);
1250         spin_lock(&uhci->lock);
1251
1252         /* If the queue is now empty, we can unlink the QH and give up its
1253          * reserved bandwidth. */
1254         if (list_empty(&qh->queue)) {
1255                 uhci_unlink_qh(uhci, qh);
1256
1257                 /* Bandwidth stuff not yet implemented */
1258         }
1259 }
1260
1261 /*
1262  * Scan the URBs in a QH's queue
1263  */
1264 #define QH_FINISHED_UNLINKING(qh)                       \
1265                 (qh->state == QH_STATE_UNLINKING &&     \
1266                 uhci->frame_number + uhci->is_stopped != qh->unlink_frame)
1267
1268 static void uhci_scan_qh(struct uhci_hcd *uhci, struct uhci_qh *qh,
1269                 struct pt_regs *regs)
1270 {
1271         struct urb_priv *urbp;
1272         struct urb *urb;
1273         int status;
1274
1275         while (!list_empty(&qh->queue)) {
1276                 urbp = list_entry(qh->queue.next, struct urb_priv, node);
1277                 urb = urbp->urb;
1278
1279                 switch (qh->type) {
1280                 case USB_ENDPOINT_XFER_CONTROL:
1281                         status = uhci_result_control(uhci, urb);
1282                         break;
1283                 case USB_ENDPOINT_XFER_ISOC:
1284                         status = uhci_result_isochronous(uhci, urb);
1285                         break;
1286                 default:        /* USB_ENDPOINT_XFER_BULK or _INT */
1287                         status = uhci_result_common(uhci, urb);
1288                         break;
1289                 }
1290                 if (status == -EINPROGRESS)
1291                         break;
1292
1293                 spin_lock(&urb->lock);
1294                 if (urb->status == -EINPROGRESS)        /* Not dequeued */
1295                         urb->status = status;
1296                 else
1297                         status = ECONNRESET;            /* Not -ECONNRESET */
1298                 spin_unlock(&urb->lock);
1299
1300                 /* Dequeued but completed URBs can't be given back unless
1301                  * the QH is stopped or has finished unlinking. */
1302                 if (status == ECONNRESET) {
1303                         if (QH_FINISHED_UNLINKING(qh))
1304                                 qh->is_stopped = 1;
1305                         else if (!qh->is_stopped)
1306                                 return;
1307                 }
1308
1309                 uhci_giveback_urb(uhci, qh, urb, regs);
1310                 if (status < 0)
1311                         break;
1312         }
1313
1314         /* If the QH is neither stopped nor finished unlinking (normal case),
1315          * our work here is done. */
1316         if (QH_FINISHED_UNLINKING(qh))
1317                 qh->is_stopped = 1;
1318         else if (!qh->is_stopped)
1319                 return;
1320
1321         /* Otherwise give back each of the dequeued URBs */
1322 restart:
1323         list_for_each_entry(urbp, &qh->queue, node) {
1324                 urb = urbp->urb;
1325                 if (urb->status != -EINPROGRESS) {
1326                         uhci_save_toggle(qh, urb);
1327                         uhci_giveback_urb(uhci, qh, urb, regs);
1328                         goto restart;
1329                 }
1330         }
1331         qh->is_stopped = 0;
1332
1333         /* There are no more dequeued URBs.  If there are still URBs on the
1334          * queue, the QH can now be re-activated. */
1335         if (!list_empty(&qh->queue)) {
1336                 if (qh->needs_fixup)
1337                         uhci_fixup_toggles(qh, 0);
1338                 uhci_activate_qh(uhci, qh);
1339         }
1340
1341         /* The queue is empty.  The QH can become idle if it is fully
1342          * unlinked. */
1343         else if (QH_FINISHED_UNLINKING(qh))
1344                 uhci_make_qh_idle(uhci, qh);
1345 }
1346
1347 static void uhci_free_pending_tds(struct uhci_hcd *uhci)
1348 {
1349         struct uhci_td *td, *tmp;
1350
1351         list_for_each_entry_safe(td, tmp, &uhci->td_remove_list, remove_list) {
1352                 list_del_init(&td->remove_list);
1353
1354                 uhci_free_td(uhci, td);
1355         }
1356 }
1357
1358 /*
1359  * Process events in the schedule, but only in one thread at a time
1360  */
1361 static void uhci_scan_schedule(struct uhci_hcd *uhci, struct pt_regs *regs)
1362 {
1363         int i;
1364         struct uhci_qh *qh;
1365
1366         /* Don't allow re-entrant calls */
1367         if (uhci->scan_in_progress) {
1368                 uhci->need_rescan = 1;
1369                 return;
1370         }
1371         uhci->scan_in_progress = 1;
1372  rescan:
1373         uhci->need_rescan = 0;
1374
1375         uhci_clear_next_interrupt(uhci);
1376         uhci_get_current_frame_number(uhci);
1377
1378         if (uhci->frame_number + uhci->is_stopped != uhci->td_remove_age)
1379                 uhci_free_pending_tds(uhci);
1380
1381         /* Go through all the QH queues and process the URBs in each one */
1382         for (i = 0; i < UHCI_NUM_SKELQH - 1; ++i) {
1383                 uhci->next_qh = list_entry(uhci->skelqh[i]->node.next,
1384                                 struct uhci_qh, node);
1385                 while ((qh = uhci->next_qh) != uhci->skelqh[i]) {
1386                         uhci->next_qh = list_entry(qh->node.next,
1387                                         struct uhci_qh, node);
1388                         uhci_scan_qh(uhci, qh, regs);
1389                 }
1390         }
1391
1392         if (uhci->need_rescan)
1393                 goto rescan;
1394         uhci->scan_in_progress = 0;
1395
1396         /* If the controller is stopped, we can finish these off right now */
1397         if (uhci->is_stopped)
1398                 uhci_free_pending_tds(uhci);
1399
1400         if (list_empty(&uhci->td_remove_list) &&
1401                         list_empty(&uhci->skel_unlink_qh->node))
1402                 uhci_clear_next_interrupt(uhci);
1403         else
1404                 uhci_set_next_interrupt(uhci);
1405 }
1406
1407 static void check_fsbr(struct uhci_hcd *uhci)
1408 {
1409         /* For now, don't scan URBs for FSBR timeouts.
1410          * Add it back in later... */
1411
1412         /* Really disable FSBR */
1413         if (!uhci->fsbr && uhci->fsbrtimeout && time_after_eq(jiffies, uhci->fsbrtimeout)) {
1414                 uhci->fsbrtimeout = 0;
1415                 uhci->skel_term_qh->link = UHCI_PTR_TERM;
1416         }
1417 }