proc: use seq_puts()/seq_putc() where possible
[linux-2.6/next.git] / drivers / usb / host / ehci-q.c
blob233c288e3f931ce4f9399d5b54f25471139f6dfb
1 /*
2 * Copyright (C) 2001-2004 by David Brownell
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the
6 * Free Software Foundation; either version 2 of the License, or (at your
7 * option) any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software Foundation,
16 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 /* this file is part of ehci-hcd.c */
21 /*-------------------------------------------------------------------------*/
24 * EHCI hardware queue manipulation ... the core. QH/QTD manipulation.
26 * Control, bulk, and interrupt traffic all use "qh" lists. They list "qtd"
27 * entries describing USB transactions, max 16-20kB/entry (with 4kB-aligned
28 * buffers needed for the larger number). We use one QH per endpoint, queue
29 * multiple urbs (all three types) per endpoint. URBs may need several qtds.
31 * ISO traffic uses "ISO TD" (itd, and sitd) records, and (along with
32 * interrupts) needs careful scheduling. Performance improvements can be
33 * an ongoing challenge. That's in "ehci-sched.c".
35 * USB 1.1 devices are handled (a) by "companion" OHCI or UHCI root hubs,
36 * or otherwise through transaction translators (TTs) in USB 2.0 hubs using
37 * (b) special fields in qh entries or (c) split iso entries. TTs will
38 * buffer low/full speed data so the host collects it at high speed.
41 /*-------------------------------------------------------------------------*/
43 /* fill a qtd, returning how much of the buffer we were able to queue up */
45 static int
46 qtd_fill(struct ehci_hcd *ehci, struct ehci_qtd *qtd, dma_addr_t buf,
47 size_t len, int token, int maxpacket)
49 int i, count;
50 u64 addr = buf;
52 /* one buffer entry per 4K ... first might be short or unaligned */
53 qtd->hw_buf[0] = cpu_to_hc32(ehci, (u32)addr);
54 qtd->hw_buf_hi[0] = cpu_to_hc32(ehci, (u32)(addr >> 32));
55 count = 0x1000 - (buf & 0x0fff); /* rest of that page */
56 if (likely (len < count)) /* ... iff needed */
57 count = len;
58 else {
59 buf += 0x1000;
60 buf &= ~0x0fff;
62 /* per-qtd limit: from 16K to 20K (best alignment) */
63 for (i = 1; count < len && i < 5; i++) {
64 addr = buf;
65 qtd->hw_buf[i] = cpu_to_hc32(ehci, (u32)addr);
66 qtd->hw_buf_hi[i] = cpu_to_hc32(ehci,
67 (u32)(addr >> 32));
68 buf += 0x1000;
69 if ((count + 0x1000) < len)
70 count += 0x1000;
71 else
72 count = len;
75 /* short packets may only terminate transfers */
76 if (count != len)
77 count -= (count % maxpacket);
79 qtd->hw_token = cpu_to_hc32(ehci, (count << 16) | token);
80 qtd->length = count;
82 return count;
85 /*-------------------------------------------------------------------------*/
87 static inline void
88 qh_update (struct ehci_hcd *ehci, struct ehci_qh *qh, struct ehci_qtd *qtd)
90 struct ehci_qh_hw *hw = qh->hw;
92 /* writes to an active overlay are unsafe */
93 BUG_ON(qh->qh_state != QH_STATE_IDLE);
95 hw->hw_qtd_next = QTD_NEXT(ehci, qtd->qtd_dma);
96 hw->hw_alt_next = EHCI_LIST_END(ehci);
98 /* Except for control endpoints, we make hardware maintain data
99 * toggle (like OHCI) ... here (re)initialize the toggle in the QH,
100 * and set the pseudo-toggle in udev. Only usb_clear_halt() will
101 * ever clear it.
103 if (!(hw->hw_info1 & cpu_to_hc32(ehci, 1 << 14))) {
104 unsigned is_out, epnum;
106 is_out = !(qtd->hw_token & cpu_to_hc32(ehci, 1 << 8));
107 epnum = (hc32_to_cpup(ehci, &hw->hw_info1) >> 8) & 0x0f;
108 if (unlikely (!usb_gettoggle (qh->dev, epnum, is_out))) {
109 hw->hw_token &= ~cpu_to_hc32(ehci, QTD_TOGGLE);
110 usb_settoggle (qh->dev, epnum, is_out, 1);
114 /* HC must see latest qtd and qh data before we clear ACTIVE+HALT */
115 wmb ();
116 hw->hw_token &= cpu_to_hc32(ehci, QTD_TOGGLE | QTD_STS_PING);
119 /* if it weren't for a common silicon quirk (writing the dummy into the qh
120 * overlay, so qh->hw_token wrongly becomes inactive/halted), only fault
121 * recovery (including urb dequeue) would need software changes to a QH...
123 static void
124 qh_refresh (struct ehci_hcd *ehci, struct ehci_qh *qh)
126 struct ehci_qtd *qtd;
128 if (list_empty (&qh->qtd_list))
129 qtd = qh->dummy;
130 else {
131 qtd = list_entry (qh->qtd_list.next,
132 struct ehci_qtd, qtd_list);
133 /* first qtd may already be partially processed */
134 if (cpu_to_hc32(ehci, qtd->qtd_dma) == qh->hw->hw_current)
135 qtd = NULL;
138 if (qtd)
139 qh_update (ehci, qh, qtd);
142 /*-------------------------------------------------------------------------*/
144 static void qh_link_async(struct ehci_hcd *ehci, struct ehci_qh *qh);
146 static void ehci_clear_tt_buffer_complete(struct usb_hcd *hcd,
147 struct usb_host_endpoint *ep)
149 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
150 struct ehci_qh *qh = ep->hcpriv;
151 unsigned long flags;
153 spin_lock_irqsave(&ehci->lock, flags);
154 qh->clearing_tt = 0;
155 if (qh->qh_state == QH_STATE_IDLE && !list_empty(&qh->qtd_list)
156 && HC_IS_RUNNING(hcd->state))
157 qh_link_async(ehci, qh);
158 spin_unlock_irqrestore(&ehci->lock, flags);
161 static void ehci_clear_tt_buffer(struct ehci_hcd *ehci, struct ehci_qh *qh,
162 struct urb *urb, u32 token)
165 /* If an async split transaction gets an error or is unlinked,
166 * the TT buffer may be left in an indeterminate state. We
167 * have to clear the TT buffer.
169 * Note: this routine is never called for Isochronous transfers.
171 if (urb->dev->tt && !usb_pipeint(urb->pipe) && !qh->clearing_tt) {
172 #ifdef DEBUG
173 struct usb_device *tt = urb->dev->tt->hub;
174 dev_dbg(&tt->dev,
175 "clear tt buffer port %d, a%d ep%d t%08x\n",
176 urb->dev->ttport, urb->dev->devnum,
177 usb_pipeendpoint(urb->pipe), token);
178 #endif /* DEBUG */
179 if (!ehci_is_TDI(ehci)
180 || urb->dev->tt->hub !=
181 ehci_to_hcd(ehci)->self.root_hub) {
182 if (usb_hub_clear_tt_buffer(urb) == 0)
183 qh->clearing_tt = 1;
184 } else {
186 /* REVISIT ARC-derived cores don't clear the root
187 * hub TT buffer in this way...
193 static int qtd_copy_status (
194 struct ehci_hcd *ehci,
195 struct urb *urb,
196 size_t length,
197 u32 token
200 int status = -EINPROGRESS;
202 /* count IN/OUT bytes, not SETUP (even short packets) */
203 if (likely (QTD_PID (token) != 2))
204 urb->actual_length += length - QTD_LENGTH (token);
206 /* don't modify error codes */
207 if (unlikely(urb->unlinked))
208 return status;
210 /* force cleanup after short read; not always an error */
211 if (unlikely (IS_SHORT_READ (token)))
212 status = -EREMOTEIO;
214 /* serious "can't proceed" faults reported by the hardware */
215 if (token & QTD_STS_HALT) {
216 if (token & QTD_STS_BABBLE) {
217 /* FIXME "must" disable babbling device's port too */
218 status = -EOVERFLOW;
219 /* CERR nonzero + halt --> stall */
220 } else if (QTD_CERR(token)) {
221 status = -EPIPE;
223 /* In theory, more than one of the following bits can be set
224 * since they are sticky and the transaction is retried.
225 * Which to test first is rather arbitrary.
227 } else if (token & QTD_STS_MMF) {
228 /* fs/ls interrupt xfer missed the complete-split */
229 status = -EPROTO;
230 } else if (token & QTD_STS_DBE) {
231 status = (QTD_PID (token) == 1) /* IN ? */
232 ? -ENOSR /* hc couldn't read data */
233 : -ECOMM; /* hc couldn't write data */
234 } else if (token & QTD_STS_XACT) {
235 /* timeout, bad CRC, wrong PID, etc */
236 ehci_dbg(ehci, "devpath %s ep%d%s 3strikes\n",
237 urb->dev->devpath,
238 usb_pipeendpoint(urb->pipe),
239 usb_pipein(urb->pipe) ? "in" : "out");
240 status = -EPROTO;
241 } else { /* unknown */
242 status = -EPROTO;
245 ehci_vdbg (ehci,
246 "dev%d ep%d%s qtd token %08x --> status %d\n",
247 usb_pipedevice (urb->pipe),
248 usb_pipeendpoint (urb->pipe),
249 usb_pipein (urb->pipe) ? "in" : "out",
250 token, status);
253 return status;
256 static void
257 ehci_urb_done(struct ehci_hcd *ehci, struct urb *urb, int status)
258 __releases(ehci->lock)
259 __acquires(ehci->lock)
261 if (likely (urb->hcpriv != NULL)) {
262 struct ehci_qh *qh = (struct ehci_qh *) urb->hcpriv;
264 /* S-mask in a QH means it's an interrupt urb */
265 if ((qh->hw->hw_info2 & cpu_to_hc32(ehci, QH_SMASK)) != 0) {
267 /* ... update hc-wide periodic stats (for usbfs) */
268 ehci_to_hcd(ehci)->self.bandwidth_int_reqs--;
270 qh_put (qh);
273 if (unlikely(urb->unlinked)) {
274 COUNT(ehci->stats.unlink);
275 } else {
276 /* report non-error and short read status as zero */
277 if (status == -EINPROGRESS || status == -EREMOTEIO)
278 status = 0;
279 COUNT(ehci->stats.complete);
282 #ifdef EHCI_URB_TRACE
283 ehci_dbg (ehci,
284 "%s %s urb %p ep%d%s status %d len %d/%d\n",
285 __func__, urb->dev->devpath, urb,
286 usb_pipeendpoint (urb->pipe),
287 usb_pipein (urb->pipe) ? "in" : "out",
288 status,
289 urb->actual_length, urb->transfer_buffer_length);
290 #endif
292 /* complete() can reenter this HCD */
293 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
294 spin_unlock (&ehci->lock);
295 usb_hcd_giveback_urb(ehci_to_hcd(ehci), urb, status);
296 spin_lock (&ehci->lock);
299 static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh);
300 static void unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh);
302 static int qh_schedule (struct ehci_hcd *ehci, struct ehci_qh *qh);
305 * Process and free completed qtds for a qh, returning URBs to drivers.
306 * Chases up to qh->hw_current. Returns number of completions called,
307 * indicating how much "real" work we did.
309 static unsigned
310 qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
312 struct ehci_qtd *last, *end = qh->dummy;
313 struct list_head *entry, *tmp;
314 int last_status;
315 int stopped;
316 unsigned count = 0;
317 u8 state;
318 const __le32 halt = HALT_BIT(ehci);
319 struct ehci_qh_hw *hw = qh->hw;
321 if (unlikely (list_empty (&qh->qtd_list)))
322 return count;
324 /* completions (or tasks on other cpus) must never clobber HALT
325 * till we've gone through and cleaned everything up, even when
326 * they add urbs to this qh's queue or mark them for unlinking.
328 * NOTE: unlinking expects to be done in queue order.
330 * It's a bug for qh->qh_state to be anything other than
331 * QH_STATE_IDLE, unless our caller is scan_async() or
332 * scan_periodic().
334 state = qh->qh_state;
335 qh->qh_state = QH_STATE_COMPLETING;
336 stopped = (state == QH_STATE_IDLE);
338 rescan:
339 last = NULL;
340 last_status = -EINPROGRESS;
341 qh->needs_rescan = 0;
343 /* remove de-activated QTDs from front of queue.
344 * after faults (including short reads), cleanup this urb
345 * then let the queue advance.
346 * if queue is stopped, handles unlinks.
348 list_for_each_safe (entry, tmp, &qh->qtd_list) {
349 struct ehci_qtd *qtd;
350 struct urb *urb;
351 u32 token = 0;
353 qtd = list_entry (entry, struct ehci_qtd, qtd_list);
354 urb = qtd->urb;
356 /* clean up any state from previous QTD ...*/
357 if (last) {
358 if (likely (last->urb != urb)) {
359 ehci_urb_done(ehci, last->urb, last_status);
360 count++;
361 last_status = -EINPROGRESS;
363 ehci_qtd_free (ehci, last);
364 last = NULL;
367 /* ignore urbs submitted during completions we reported */
368 if (qtd == end)
369 break;
371 /* hardware copies qtd out of qh overlay */
372 rmb ();
373 token = hc32_to_cpu(ehci, qtd->hw_token);
375 /* always clean up qtds the hc de-activated */
376 retry_xacterr:
377 if ((token & QTD_STS_ACTIVE) == 0) {
379 /* on STALL, error, and short reads this urb must
380 * complete and all its qtds must be recycled.
382 if ((token & QTD_STS_HALT) != 0) {
384 /* retry transaction errors until we
385 * reach the software xacterr limit
387 if ((token & QTD_STS_XACT) &&
388 QTD_CERR(token) == 0 &&
389 ++qh->xacterrs < QH_XACTERR_MAX &&
390 !urb->unlinked) {
391 ehci_dbg(ehci,
392 "detected XactErr len %zu/%zu retry %d\n",
393 qtd->length - QTD_LENGTH(token), qtd->length, qh->xacterrs);
395 /* reset the token in the qtd and the
396 * qh overlay (which still contains
397 * the qtd) so that we pick up from
398 * where we left off
400 token &= ~QTD_STS_HALT;
401 token |= QTD_STS_ACTIVE |
402 (EHCI_TUNE_CERR << 10);
403 qtd->hw_token = cpu_to_hc32(ehci,
404 token);
405 wmb();
406 hw->hw_token = cpu_to_hc32(ehci,
407 token);
408 goto retry_xacterr;
410 stopped = 1;
412 /* magic dummy for some short reads; qh won't advance.
413 * that silicon quirk can kick in with this dummy too.
415 * other short reads won't stop the queue, including
416 * control transfers (status stage handles that) or
417 * most other single-qtd reads ... the queue stops if
418 * URB_SHORT_NOT_OK was set so the driver submitting
419 * the urbs could clean it up.
421 } else if (IS_SHORT_READ (token)
422 && !(qtd->hw_alt_next
423 & EHCI_LIST_END(ehci))) {
424 stopped = 1;
425 goto halt;
428 /* stop scanning when we reach qtds the hc is using */
429 } else if (likely (!stopped
430 && HC_IS_RUNNING (ehci_to_hcd(ehci)->state))) {
431 break;
433 /* scan the whole queue for unlinks whenever it stops */
434 } else {
435 stopped = 1;
437 /* cancel everything if we halt, suspend, etc */
438 if (!HC_IS_RUNNING(ehci_to_hcd(ehci)->state))
439 last_status = -ESHUTDOWN;
441 /* this qtd is active; skip it unless a previous qtd
442 * for its urb faulted, or its urb was canceled.
444 else if (last_status == -EINPROGRESS && !urb->unlinked)
445 continue;
447 /* qh unlinked; token in overlay may be most current */
448 if (state == QH_STATE_IDLE
449 && cpu_to_hc32(ehci, qtd->qtd_dma)
450 == hw->hw_current) {
451 token = hc32_to_cpu(ehci, hw->hw_token);
453 /* An unlink may leave an incomplete
454 * async transaction in the TT buffer.
455 * We have to clear it.
457 ehci_clear_tt_buffer(ehci, qh, urb, token);
460 /* force halt for unlinked or blocked qh, so we'll
461 * patch the qh later and so that completions can't
462 * activate it while we "know" it's stopped.
464 if ((halt & hw->hw_token) == 0) {
465 halt:
466 hw->hw_token |= halt;
467 wmb ();
471 /* unless we already know the urb's status, collect qtd status
472 * and update count of bytes transferred. in common short read
473 * cases with only one data qtd (including control transfers),
474 * queue processing won't halt. but with two or more qtds (for
475 * example, with a 32 KB transfer), when the first qtd gets a
476 * short read the second must be removed by hand.
478 if (last_status == -EINPROGRESS) {
479 last_status = qtd_copy_status(ehci, urb,
480 qtd->length, token);
481 if (last_status == -EREMOTEIO
482 && (qtd->hw_alt_next
483 & EHCI_LIST_END(ehci)))
484 last_status = -EINPROGRESS;
486 /* As part of low/full-speed endpoint-halt processing
487 * we must clear the TT buffer (11.17.5).
489 if (unlikely(last_status != -EINPROGRESS &&
490 last_status != -EREMOTEIO)) {
491 /* The TT's in some hubs malfunction when they
492 * receive this request following a STALL (they
493 * stop sending isochronous packets). Since a
494 * STALL can't leave the TT buffer in a busy
495 * state (if you believe Figures 11-48 - 11-51
496 * in the USB 2.0 spec), we won't clear the TT
497 * buffer in this case. Strictly speaking this
498 * is a violation of the spec.
500 if (last_status != -EPIPE)
501 ehci_clear_tt_buffer(ehci, qh, urb,
502 token);
506 /* if we're removing something not at the queue head,
507 * patch the hardware queue pointer.
509 if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {
510 last = list_entry (qtd->qtd_list.prev,
511 struct ehci_qtd, qtd_list);
512 last->hw_next = qtd->hw_next;
515 /* remove qtd; it's recycled after possible urb completion */
516 list_del (&qtd->qtd_list);
517 last = qtd;
519 /* reinit the xacterr counter for the next qtd */
520 qh->xacterrs = 0;
523 /* last urb's completion might still need calling */
524 if (likely (last != NULL)) {
525 ehci_urb_done(ehci, last->urb, last_status);
526 count++;
527 ehci_qtd_free (ehci, last);
530 /* Do we need to rescan for URBs dequeued during a giveback? */
531 if (unlikely(qh->needs_rescan)) {
532 /* If the QH is already unlinked, do the rescan now. */
533 if (state == QH_STATE_IDLE)
534 goto rescan;
536 /* Otherwise we have to wait until the QH is fully unlinked.
537 * Our caller will start an unlink if qh->needs_rescan is
538 * set. But if an unlink has already started, nothing needs
539 * to be done.
541 if (state != QH_STATE_LINKED)
542 qh->needs_rescan = 0;
545 /* restore original state; caller must unlink or relink */
546 qh->qh_state = state;
548 /* be sure the hardware's done with the qh before refreshing
549 * it after fault cleanup, or recovering from silicon wrongly
550 * overlaying the dummy qtd (which reduces DMA chatter).
552 if (stopped != 0 || hw->hw_qtd_next == EHCI_LIST_END(ehci)) {
553 switch (state) {
554 case QH_STATE_IDLE:
555 qh_refresh(ehci, qh);
556 break;
557 case QH_STATE_LINKED:
558 /* We won't refresh a QH that's linked (after the HC
559 * stopped the queue). That avoids a race:
560 * - HC reads first part of QH;
561 * - CPU updates that first part and the token;
562 * - HC reads rest of that QH, including token
563 * Result: HC gets an inconsistent image, and then
564 * DMAs to/from the wrong memory (corrupting it).
566 * That should be rare for interrupt transfers,
567 * except maybe high bandwidth ...
570 /* Tell the caller to start an unlink */
571 qh->needs_rescan = 1;
572 break;
573 /* otherwise, unlink already started */
577 return count;
580 /*-------------------------------------------------------------------------*/
582 // high bandwidth multiplier, as encoded in highspeed endpoint descriptors
583 #define hb_mult(wMaxPacketSize) (1 + (((wMaxPacketSize) >> 11) & 0x03))
584 // ... and packet size, for any kind of endpoint descriptor
585 #define max_packet(wMaxPacketSize) ((wMaxPacketSize) & 0x07ff)
588 * reverse of qh_urb_transaction: free a list of TDs.
589 * used for cleanup after errors, before HC sees an URB's TDs.
591 static void qtd_list_free (
592 struct ehci_hcd *ehci,
593 struct urb *urb,
594 struct list_head *qtd_list
596 struct list_head *entry, *temp;
598 list_for_each_safe (entry, temp, qtd_list) {
599 struct ehci_qtd *qtd;
601 qtd = list_entry (entry, struct ehci_qtd, qtd_list);
602 list_del (&qtd->qtd_list);
603 ehci_qtd_free (ehci, qtd);
608 * create a list of filled qtds for this URB; won't link into qh.
610 static struct list_head *
611 qh_urb_transaction (
612 struct ehci_hcd *ehci,
613 struct urb *urb,
614 struct list_head *head,
615 gfp_t flags
617 struct ehci_qtd *qtd, *qtd_prev;
618 dma_addr_t buf;
619 int len, this_sg_len, maxpacket;
620 int is_input;
621 u32 token;
622 int i;
623 struct scatterlist *sg;
626 * URBs map to sequences of QTDs: one logical transaction
628 qtd = ehci_qtd_alloc (ehci, flags);
629 if (unlikely (!qtd))
630 return NULL;
631 list_add_tail (&qtd->qtd_list, head);
632 qtd->urb = urb;
634 token = QTD_STS_ACTIVE;
635 token |= (EHCI_TUNE_CERR << 10);
636 /* for split transactions, SplitXState initialized to zero */
638 len = urb->transfer_buffer_length;
639 is_input = usb_pipein (urb->pipe);
640 if (usb_pipecontrol (urb->pipe)) {
641 /* SETUP pid */
642 qtd_fill(ehci, qtd, urb->setup_dma,
643 sizeof (struct usb_ctrlrequest),
644 token | (2 /* "setup" */ << 8), 8);
646 /* ... and always at least one more pid */
647 token ^= QTD_TOGGLE;
648 qtd_prev = qtd;
649 qtd = ehci_qtd_alloc (ehci, flags);
650 if (unlikely (!qtd))
651 goto cleanup;
652 qtd->urb = urb;
653 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
654 list_add_tail (&qtd->qtd_list, head);
656 /* for zero length DATA stages, STATUS is always IN */
657 if (len == 0)
658 token |= (1 /* "in" */ << 8);
662 * data transfer stage: buffer setup
664 i = urb->num_sgs;
665 if (len > 0 && i > 0) {
666 sg = urb->sg;
667 buf = sg_dma_address(sg);
669 /* urb->transfer_buffer_length may be smaller than the
670 * size of the scatterlist (or vice versa)
672 this_sg_len = min_t(int, sg_dma_len(sg), len);
673 } else {
674 sg = NULL;
675 buf = urb->transfer_dma;
676 this_sg_len = len;
679 if (is_input)
680 token |= (1 /* "in" */ << 8);
681 /* else it's already initted to "out" pid (0 << 8) */
683 maxpacket = max_packet(usb_maxpacket(urb->dev, urb->pipe, !is_input));
686 * buffer gets wrapped in one or more qtds;
687 * last one may be "short" (including zero len)
688 * and may serve as a control status ack
690 for (;;) {
691 int this_qtd_len;
693 this_qtd_len = qtd_fill(ehci, qtd, buf, this_sg_len, token,
694 maxpacket);
695 this_sg_len -= this_qtd_len;
696 len -= this_qtd_len;
697 buf += this_qtd_len;
700 * short reads advance to a "magic" dummy instead of the next
701 * qtd ... that forces the queue to stop, for manual cleanup.
702 * (this will usually be overridden later.)
704 if (is_input)
705 qtd->hw_alt_next = ehci->async->hw->hw_alt_next;
707 /* qh makes control packets use qtd toggle; maybe switch it */
708 if ((maxpacket & (this_qtd_len + (maxpacket - 1))) == 0)
709 token ^= QTD_TOGGLE;
711 if (likely(this_sg_len <= 0)) {
712 if (--i <= 0 || len <= 0)
713 break;
714 sg = sg_next(sg);
715 buf = sg_dma_address(sg);
716 this_sg_len = min_t(int, sg_dma_len(sg), len);
719 qtd_prev = qtd;
720 qtd = ehci_qtd_alloc (ehci, flags);
721 if (unlikely (!qtd))
722 goto cleanup;
723 qtd->urb = urb;
724 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
725 list_add_tail (&qtd->qtd_list, head);
729 * unless the caller requires manual cleanup after short reads,
730 * have the alt_next mechanism keep the queue running after the
731 * last data qtd (the only one, for control and most other cases).
733 if (likely ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0
734 || usb_pipecontrol (urb->pipe)))
735 qtd->hw_alt_next = EHCI_LIST_END(ehci);
738 * control requests may need a terminating data "status" ack;
739 * bulk ones may need a terminating short packet (zero length).
741 if (likely (urb->transfer_buffer_length != 0)) {
742 int one_more = 0;
744 if (usb_pipecontrol (urb->pipe)) {
745 one_more = 1;
746 token ^= 0x0100; /* "in" <--> "out" */
747 token |= QTD_TOGGLE; /* force DATA1 */
748 } else if (usb_pipebulk (urb->pipe)
749 && (urb->transfer_flags & URB_ZERO_PACKET)
750 && !(urb->transfer_buffer_length % maxpacket)) {
751 one_more = 1;
753 if (one_more) {
754 qtd_prev = qtd;
755 qtd = ehci_qtd_alloc (ehci, flags);
756 if (unlikely (!qtd))
757 goto cleanup;
758 qtd->urb = urb;
759 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
760 list_add_tail (&qtd->qtd_list, head);
762 /* never any data in such packets */
763 qtd_fill(ehci, qtd, 0, 0, token, 0);
767 /* by default, enable interrupt on urb completion */
768 if (likely (!(urb->transfer_flags & URB_NO_INTERRUPT)))
769 qtd->hw_token |= cpu_to_hc32(ehci, QTD_IOC);
770 return head;
772 cleanup:
773 qtd_list_free (ehci, urb, head);
774 return NULL;
777 /*-------------------------------------------------------------------------*/
779 // Would be best to create all qh's from config descriptors,
780 // when each interface/altsetting is established. Unlink
781 // any previous qh and cancel its urbs first; endpoints are
782 // implicitly reset then (data toggle too).
783 // That'd mean updating how usbcore talks to HCDs. (2.7?)
787 * Each QH holds a qtd list; a QH is used for everything except iso.
789 * For interrupt urbs, the scheduler must set the microframe scheduling
790 * mask(s) each time the QH gets scheduled. For highspeed, that's
791 * just one microframe in the s-mask. For split interrupt transactions
792 * there are additional complications: c-mask, maybe FSTNs.
794 static struct ehci_qh *
795 qh_make (
796 struct ehci_hcd *ehci,
797 struct urb *urb,
798 gfp_t flags
800 struct ehci_qh *qh = ehci_qh_alloc (ehci, flags);
801 u32 info1 = 0, info2 = 0;
802 int is_input, type;
803 int maxp = 0;
804 struct usb_tt *tt = urb->dev->tt;
805 struct ehci_qh_hw *hw;
807 if (!qh)
808 return qh;
811 * init endpoint/device data for this QH
813 info1 |= usb_pipeendpoint (urb->pipe) << 8;
814 info1 |= usb_pipedevice (urb->pipe) << 0;
816 is_input = usb_pipein (urb->pipe);
817 type = usb_pipetype (urb->pipe);
818 maxp = usb_maxpacket (urb->dev, urb->pipe, !is_input);
820 /* 1024 byte maxpacket is a hardware ceiling. High bandwidth
821 * acts like up to 3KB, but is built from smaller packets.
823 if (max_packet(maxp) > 1024) {
824 ehci_dbg(ehci, "bogus qh maxpacket %d\n", max_packet(maxp));
825 goto done;
828 /* Compute interrupt scheduling parameters just once, and save.
829 * - allowing for high bandwidth, how many nsec/uframe are used?
830 * - split transactions need a second CSPLIT uframe; same question
831 * - splits also need a schedule gap (for full/low speed I/O)
832 * - qh has a polling interval
834 * For control/bulk requests, the HC or TT handles these.
836 if (type == PIPE_INTERRUPT) {
837 qh->usecs = NS_TO_US(usb_calc_bus_time(USB_SPEED_HIGH,
838 is_input, 0,
839 hb_mult(maxp) * max_packet(maxp)));
840 qh->start = NO_FRAME;
842 if (urb->dev->speed == USB_SPEED_HIGH) {
843 qh->c_usecs = 0;
844 qh->gap_uf = 0;
846 qh->period = urb->interval >> 3;
847 if (qh->period == 0 && urb->interval != 1) {
848 /* NOTE interval 2 or 4 uframes could work.
849 * But interval 1 scheduling is simpler, and
850 * includes high bandwidth.
852 urb->interval = 1;
853 } else if (qh->period > ehci->periodic_size) {
854 qh->period = ehci->periodic_size;
855 urb->interval = qh->period << 3;
857 } else {
858 int think_time;
860 /* gap is f(FS/LS transfer times) */
861 qh->gap_uf = 1 + usb_calc_bus_time (urb->dev->speed,
862 is_input, 0, maxp) / (125 * 1000);
864 /* FIXME this just approximates SPLIT/CSPLIT times */
865 if (is_input) { // SPLIT, gap, CSPLIT+DATA
866 qh->c_usecs = qh->usecs + HS_USECS (0);
867 qh->usecs = HS_USECS (1);
868 } else { // SPLIT+DATA, gap, CSPLIT
869 qh->usecs += HS_USECS (1);
870 qh->c_usecs = HS_USECS (0);
873 think_time = tt ? tt->think_time : 0;
874 qh->tt_usecs = NS_TO_US (think_time +
875 usb_calc_bus_time (urb->dev->speed,
876 is_input, 0, max_packet (maxp)));
877 qh->period = urb->interval;
878 if (qh->period > ehci->periodic_size) {
879 qh->period = ehci->periodic_size;
880 urb->interval = qh->period;
885 /* support for tt scheduling, and access to toggles */
886 qh->dev = urb->dev;
888 /* using TT? */
889 switch (urb->dev->speed) {
890 case USB_SPEED_LOW:
891 info1 |= (1 << 12); /* EPS "low" */
892 /* FALL THROUGH */
894 case USB_SPEED_FULL:
895 /* EPS 0 means "full" */
896 if (type != PIPE_INTERRUPT)
897 info1 |= (EHCI_TUNE_RL_TT << 28);
898 if (type == PIPE_CONTROL) {
899 info1 |= (1 << 27); /* for TT */
900 info1 |= 1 << 14; /* toggle from qtd */
902 info1 |= maxp << 16;
904 info2 |= (EHCI_TUNE_MULT_TT << 30);
906 /* Some Freescale processors have an erratum in which the
907 * port number in the queue head was 0..N-1 instead of 1..N.
909 if (ehci_has_fsl_portno_bug(ehci))
910 info2 |= (urb->dev->ttport-1) << 23;
911 else
912 info2 |= urb->dev->ttport << 23;
914 /* set the address of the TT; for TDI's integrated
915 * root hub tt, leave it zeroed.
917 if (tt && tt->hub != ehci_to_hcd(ehci)->self.root_hub)
918 info2 |= tt->hub->devnum << 16;
920 /* NOTE: if (PIPE_INTERRUPT) { scheduler sets c-mask } */
922 break;
924 case USB_SPEED_HIGH: /* no TT involved */
925 info1 |= (2 << 12); /* EPS "high" */
926 if (type == PIPE_CONTROL) {
927 info1 |= (EHCI_TUNE_RL_HS << 28);
928 info1 |= 64 << 16; /* usb2 fixed maxpacket */
929 info1 |= 1 << 14; /* toggle from qtd */
930 info2 |= (EHCI_TUNE_MULT_HS << 30);
931 } else if (type == PIPE_BULK) {
932 info1 |= (EHCI_TUNE_RL_HS << 28);
933 /* The USB spec says that high speed bulk endpoints
934 * always use 512 byte maxpacket. But some device
935 * vendors decided to ignore that, and MSFT is happy
936 * to help them do so. So now people expect to use
937 * such nonconformant devices with Linux too; sigh.
939 info1 |= max_packet(maxp) << 16;
940 info2 |= (EHCI_TUNE_MULT_HS << 30);
941 } else { /* PIPE_INTERRUPT */
942 info1 |= max_packet (maxp) << 16;
943 info2 |= hb_mult (maxp) << 30;
945 break;
946 default:
947 dbg ("bogus dev %p speed %d", urb->dev, urb->dev->speed);
948 done:
949 qh_put (qh);
950 return NULL;
953 /* NOTE: if (PIPE_INTERRUPT) { scheduler sets s-mask } */
955 /* init as live, toggle clear, advance to dummy */
956 qh->qh_state = QH_STATE_IDLE;
957 hw = qh->hw;
958 hw->hw_info1 = cpu_to_hc32(ehci, info1);
959 hw->hw_info2 = cpu_to_hc32(ehci, info2);
960 usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe), !is_input, 1);
961 qh_refresh (ehci, qh);
962 return qh;
965 /*-------------------------------------------------------------------------*/
967 /* move qh (and its qtds) onto async queue; maybe enable queue. */
969 static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
971 __hc32 dma = QH_NEXT(ehci, qh->qh_dma);
972 struct ehci_qh *head;
974 /* Don't link a QH if there's a Clear-TT-Buffer pending */
975 if (unlikely(qh->clearing_tt))
976 return;
978 WARN_ON(qh->qh_state != QH_STATE_IDLE);
980 /* (re)start the async schedule? */
981 head = ehci->async;
982 timer_action_done (ehci, TIMER_ASYNC_OFF);
983 if (!head->qh_next.qh) {
984 u32 cmd = ehci_readl(ehci, &ehci->regs->command);
986 if (!(cmd & CMD_ASE)) {
987 /* in case a clear of CMD_ASE didn't take yet */
988 (void)handshake(ehci, &ehci->regs->status,
989 STS_ASS, 0, 150);
990 cmd |= CMD_ASE | CMD_RUN;
991 ehci_writel(ehci, cmd, &ehci->regs->command);
992 ehci_to_hcd(ehci)->state = HC_STATE_RUNNING;
993 /* posted write need not be known to HC yet ... */
997 /* clear halt and/or toggle; and maybe recover from silicon quirk */
998 qh_refresh(ehci, qh);
1000 /* splice right after start */
1001 qh->qh_next = head->qh_next;
1002 qh->hw->hw_next = head->hw->hw_next;
1003 wmb ();
1005 head->qh_next.qh = qh;
1006 head->hw->hw_next = dma;
1008 qh_get(qh);
1009 qh->xacterrs = 0;
1010 qh->qh_state = QH_STATE_LINKED;
1011 /* qtd completions reported later by interrupt */
1014 /*-------------------------------------------------------------------------*/
1017 * For control/bulk/interrupt, return QH with these TDs appended.
1018 * Allocates and initializes the QH if necessary.
1019 * Returns null if it can't allocate a QH it needs to.
1020 * If the QH has TDs (urbs) already, that's great.
1022 static struct ehci_qh *qh_append_tds (
1023 struct ehci_hcd *ehci,
1024 struct urb *urb,
1025 struct list_head *qtd_list,
1026 int epnum,
1027 void **ptr
1030 struct ehci_qh *qh = NULL;
1031 __hc32 qh_addr_mask = cpu_to_hc32(ehci, 0x7f);
1033 qh = (struct ehci_qh *) *ptr;
1034 if (unlikely (qh == NULL)) {
1035 /* can't sleep here, we have ehci->lock... */
1036 qh = qh_make (ehci, urb, GFP_ATOMIC);
1037 *ptr = qh;
1039 if (likely (qh != NULL)) {
1040 struct ehci_qtd *qtd;
1042 if (unlikely (list_empty (qtd_list)))
1043 qtd = NULL;
1044 else
1045 qtd = list_entry (qtd_list->next, struct ehci_qtd,
1046 qtd_list);
1048 /* control qh may need patching ... */
1049 if (unlikely (epnum == 0)) {
1051 /* usb_reset_device() briefly reverts to address 0 */
1052 if (usb_pipedevice (urb->pipe) == 0)
1053 qh->hw->hw_info1 &= ~qh_addr_mask;
1056 /* just one way to queue requests: swap with the dummy qtd.
1057 * only hc or qh_refresh() ever modify the overlay.
1059 if (likely (qtd != NULL)) {
1060 struct ehci_qtd *dummy;
1061 dma_addr_t dma;
1062 __hc32 token;
1064 /* to avoid racing the HC, use the dummy td instead of
1065 * the first td of our list (becomes new dummy). both
1066 * tds stay deactivated until we're done, when the
1067 * HC is allowed to fetch the old dummy (4.10.2).
1069 token = qtd->hw_token;
1070 qtd->hw_token = HALT_BIT(ehci);
1071 wmb ();
1072 dummy = qh->dummy;
1074 dma = dummy->qtd_dma;
1075 *dummy = *qtd;
1076 dummy->qtd_dma = dma;
1078 list_del (&qtd->qtd_list);
1079 list_add (&dummy->qtd_list, qtd_list);
1080 list_splice_tail(qtd_list, &qh->qtd_list);
1082 ehci_qtd_init(ehci, qtd, qtd->qtd_dma);
1083 qh->dummy = qtd;
1085 /* hc must see the new dummy at list end */
1086 dma = qtd->qtd_dma;
1087 qtd = list_entry (qh->qtd_list.prev,
1088 struct ehci_qtd, qtd_list);
1089 qtd->hw_next = QTD_NEXT(ehci, dma);
1091 /* let the hc process these next qtds */
1092 wmb ();
1093 dummy->hw_token = token;
1095 urb->hcpriv = qh_get (qh);
1098 return qh;
1101 /*-------------------------------------------------------------------------*/
1103 static int
1104 submit_async (
1105 struct ehci_hcd *ehci,
1106 struct urb *urb,
1107 struct list_head *qtd_list,
1108 gfp_t mem_flags
1110 struct ehci_qtd *qtd;
1111 int epnum;
1112 unsigned long flags;
1113 struct ehci_qh *qh = NULL;
1114 int rc;
1116 qtd = list_entry (qtd_list->next, struct ehci_qtd, qtd_list);
1117 epnum = urb->ep->desc.bEndpointAddress;
1119 #ifdef EHCI_URB_TRACE
1120 ehci_dbg (ehci,
1121 "%s %s urb %p ep%d%s len %d, qtd %p [qh %p]\n",
1122 __func__, urb->dev->devpath, urb,
1123 epnum & 0x0f, (epnum & USB_DIR_IN) ? "in" : "out",
1124 urb->transfer_buffer_length,
1125 qtd, urb->ep->hcpriv);
1126 #endif
1128 spin_lock_irqsave (&ehci->lock, flags);
1129 if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
1130 rc = -ESHUTDOWN;
1131 goto done;
1133 rc = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
1134 if (unlikely(rc))
1135 goto done;
1137 qh = qh_append_tds(ehci, urb, qtd_list, epnum, &urb->ep->hcpriv);
1138 if (unlikely(qh == NULL)) {
1139 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
1140 rc = -ENOMEM;
1141 goto done;
1144 /* Control/bulk operations through TTs don't need scheduling,
1145 * the HC and TT handle it when the TT has a buffer ready.
1147 if (likely (qh->qh_state == QH_STATE_IDLE))
1148 qh_link_async(ehci, qh);
1149 done:
1150 spin_unlock_irqrestore (&ehci->lock, flags);
1151 if (unlikely (qh == NULL))
1152 qtd_list_free (ehci, urb, qtd_list);
1153 return rc;
1156 /*-------------------------------------------------------------------------*/
1158 /* the async qh for the qtds being reclaimed are now unlinked from the HC */
1160 static void end_unlink_async (struct ehci_hcd *ehci)
1162 struct ehci_qh *qh = ehci->reclaim;
1163 struct ehci_qh *next;
1165 iaa_watchdog_done(ehci);
1167 // qh->hw_next = cpu_to_hc32(qh->qh_dma);
1168 qh->qh_state = QH_STATE_IDLE;
1169 qh->qh_next.qh = NULL;
1170 qh_put (qh); // refcount from reclaim
1172 /* other unlink(s) may be pending (in QH_STATE_UNLINK_WAIT) */
1173 next = qh->reclaim;
1174 ehci->reclaim = next;
1175 qh->reclaim = NULL;
1177 qh_completions (ehci, qh);
1179 if (!list_empty (&qh->qtd_list)
1180 && HC_IS_RUNNING (ehci_to_hcd(ehci)->state))
1181 qh_link_async (ehci, qh);
1182 else {
1183 /* it's not free to turn the async schedule on/off; leave it
1184 * active but idle for a while once it empties.
1186 if (HC_IS_RUNNING (ehci_to_hcd(ehci)->state)
1187 && ehci->async->qh_next.qh == NULL)
1188 timer_action (ehci, TIMER_ASYNC_OFF);
1190 qh_put(qh); /* refcount from async list */
1192 if (next) {
1193 ehci->reclaim = NULL;
1194 start_unlink_async (ehci, next);
1198 /* makes sure the async qh will become idle */
1199 /* caller must own ehci->lock */
1201 static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
1203 int cmd = ehci_readl(ehci, &ehci->regs->command);
1204 struct ehci_qh *prev;
1206 #ifdef DEBUG
1207 assert_spin_locked(&ehci->lock);
1208 if (ehci->reclaim
1209 || (qh->qh_state != QH_STATE_LINKED
1210 && qh->qh_state != QH_STATE_UNLINK_WAIT)
1212 BUG ();
1213 #endif
1215 /* stop async schedule right now? */
1216 if (unlikely (qh == ehci->async)) {
1217 /* can't get here without STS_ASS set */
1218 if (ehci_to_hcd(ehci)->state != HC_STATE_HALT
1219 && !ehci->reclaim) {
1220 /* ... and CMD_IAAD clear */
1221 ehci_writel(ehci, cmd & ~CMD_ASE,
1222 &ehci->regs->command);
1223 wmb ();
1224 // handshake later, if we need to
1225 timer_action_done (ehci, TIMER_ASYNC_OFF);
1227 return;
1230 qh->qh_state = QH_STATE_UNLINK;
1231 ehci->reclaim = qh = qh_get (qh);
1233 prev = ehci->async;
1234 while (prev->qh_next.qh != qh)
1235 prev = prev->qh_next.qh;
1237 prev->hw->hw_next = qh->hw->hw_next;
1238 prev->qh_next = qh->qh_next;
1239 wmb ();
1241 /* If the controller isn't running, we don't have to wait for it */
1242 if (unlikely(!HC_IS_RUNNING(ehci_to_hcd(ehci)->state))) {
1243 /* if (unlikely (qh->reclaim != 0))
1244 * this will recurse, probably not much
1246 end_unlink_async (ehci);
1247 return;
1250 cmd |= CMD_IAAD;
1251 ehci_writel(ehci, cmd, &ehci->regs->command);
1252 (void)ehci_readl(ehci, &ehci->regs->command);
1253 iaa_watchdog_start(ehci);
1256 /*-------------------------------------------------------------------------*/
1258 static void scan_async (struct ehci_hcd *ehci)
1260 struct ehci_qh *qh;
1261 enum ehci_timer_action action = TIMER_IO_WATCHDOG;
1263 ehci->stamp = ehci_readl(ehci, &ehci->regs->frame_index);
1264 timer_action_done (ehci, TIMER_ASYNC_SHRINK);
1265 rescan:
1266 qh = ehci->async->qh_next.qh;
1267 if (likely (qh != NULL)) {
1268 do {
1269 /* clean any finished work for this qh */
1270 if (!list_empty (&qh->qtd_list)
1271 && qh->stamp != ehci->stamp) {
1272 int temp;
1274 /* unlinks could happen here; completion
1275 * reporting drops the lock. rescan using
1276 * the latest schedule, but don't rescan
1277 * qhs we already finished (no looping).
1279 qh = qh_get (qh);
1280 qh->stamp = ehci->stamp;
1281 temp = qh_completions (ehci, qh);
1282 if (qh->needs_rescan)
1283 unlink_async(ehci, qh);
1284 qh_put (qh);
1285 if (temp != 0) {
1286 goto rescan;
1290 /* unlink idle entries, reducing DMA usage as well
1291 * as HCD schedule-scanning costs. delay for any qh
1292 * we just scanned, there's a not-unusual case that it
1293 * doesn't stay idle for long.
1294 * (plus, avoids some kind of re-activation race.)
1296 if (list_empty(&qh->qtd_list)
1297 && qh->qh_state == QH_STATE_LINKED) {
1298 if (!ehci->reclaim
1299 && ((ehci->stamp - qh->stamp) & 0x1fff)
1300 >= (EHCI_SHRINK_FRAMES * 8))
1301 start_unlink_async(ehci, qh);
1302 else
1303 action = TIMER_ASYNC_SHRINK;
1306 qh = qh->qh_next.qh;
1307 } while (qh);
1309 if (action == TIMER_ASYNC_SHRINK)
1310 timer_action (ehci, TIMER_ASYNC_SHRINK);