1 /*
2 * Copyright (C) 2001-2004 by David Brownell
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the
6 * Free Software Foundation; either version 2 of the License, or (at your
7 * option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software Foundation,
16 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19 /* this file is part of ehci-hcd.c */
20
21 /*-------------------------------------------------------------------------*/
22
23 /*
24 * EHCI hardware queue manipulation ... the core. QH/QTD manipulation.
25 *
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.
30 *
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".
34 *
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.
39 */
40
41 /*-------------------------------------------------------------------------*/
42
43 /* fill a qtd, returning how much of the buffer we were able to queue up */
44 // 该函数用于填充qtd结构，并返回当前qtd所承载的数据长度，
45 // 每个qtd有5个pionter，每个pionter最大索引范围4k，因此，每个qtd最大索引5*4k
46 // 该函数填充pionter，把指针与要指向的物理地址关联起来
47 // #include "sunxi_hal_timer.h"
48
49 static int
qtd_fill(struct ehci_hcd * ehci,struct ehci_qtd * qtd,dma_addr_t buf,size_t len,int token,int maxpacket)50 qtd_fill(struct ehci_hcd *ehci, struct ehci_qtd *qtd, dma_addr_t buf,
51 size_t len, int token, int maxpacket)
52 {
53 int i, count;
54 u64 addr = buf;
55
56 /* one buffer entry per 4K ... first might be short or unaligned */
57 qtd->hw_buf[0] = cpu_to_hc32(ehci, (u32)addr);
58 qtd->hw_buf_hi[0] = cpu_to_hc32(ehci, (u32)(addr >> 32));
59 count = 0x1000 - (buf & 0x0fff); /* rest of that page */
60 if (len < count) /* ... iff needed */
61 count = len;
62 else {
63 buf += 0x1000;
64 buf &= ~0x0fff;
65
66 /* per-qtd limit: from 16K to 20K (best alignment) */
67 for (i = 1; count < len && i < 5; i++) {
68 addr = buf;
69 qtd->hw_buf[i] = cpu_to_hc32(ehci, (u32)addr);
70 qtd->hw_buf_hi[i] = cpu_to_hc32(ehci,
71 (u32)(addr >> 32));
72 buf += 0x1000;
73 if ((count + 0x1000) < len)
74 count += 0x1000;
75 else
76 count = len;
77 }
78
79 /* short packets may only terminate transfers */
80 if (count != len)
81 count -= (count % maxpacket);
82 }
83 qtd->hw_token = cpu_to_hc32(ehci, (count << 16) | token);
84 qtd->length = count;
85
86 EHCI_DEBUG_PRINTF("qtd->hw_token = 0x%lx, qtd->length = 0x%x",
87 qtd->hw_token, qtd->length);
88
89 return count;
90 }
91
92 /*-------------------------------------------------------------------------*/
93
94 static inline void
qh_update(struct ehci_hcd * ehci,struct ehci_qh * qh,struct ehci_qtd * qtd)95 qh_update (struct ehci_hcd *ehci, struct ehci_qh *qh, struct ehci_qtd *qtd)
96 {
97 struct ehci_qh_hw *hw = qh->hw;
98
99 /* writes to an active overlay are unsafe */
100 //WARN_ON(qh->qh_state != QH_STATE_IDLE);
101
102 hw->hw_qtd_next = QTD_NEXT(ehci, qtd->qtd_dma);
103 hw->hw_alt_next = EHCI_LIST_END(ehci);
104
105 /* Except for control endpoints, we make hardware maintain data
106 * toggle (like OHCI) ... here (re)initialize the toggle in the QH,
107 * and set the pseudo-toggle in udev. Only usb_clear_halt() will
108 * ever clear it.
109 */
110 if (!(hw->hw_info1 & cpu_to_hc32(ehci, QH_TOGGLE_CTL))) {
111 unsigned is_out, epnum;
112
113 is_out = qh->is_out;
114 epnum = (hc32_to_cpup(ehci, &hw->hw_info1) >> 8) & 0x0f;
115 if (!usb_gettoggle(qh->ps.udev, epnum, is_out)) {
116 hw->hw_token &= ~cpu_to_hc32(ehci, QTD_TOGGLE);
117 usb_settoggle(qh->ps.udev, epnum, is_out, 1);
118 }
119 }
120
121 hw->hw_token &= cpu_to_hc32(ehci, QTD_TOGGLE | QTD_STS_PING);
122 }
123
124 /* if it weren't for a common silicon quirk (writing the dummy into the qh
125 * overlay, so qh->hw_token wrongly becomes inactive/halted), only fault
126 * recovery (including urb dequeue) would need software changes to a QH...
127 */
128 static void
qh_refresh(struct ehci_hcd * ehci,struct ehci_qh * qh)129 qh_refresh (struct ehci_hcd *ehci, struct ehci_qh *qh)
130 {
131 struct ehci_qtd *qtd;
132
133 qtd = list_entry(qh->qtd_list.next, struct ehci_qtd, qtd_list);
134
135 /*
136 * first qtd may already be partially processed.
137 * If we come here during unlink, the QH overlay region
138 * might have reference to the just unlinked qtd. The
139 * qtd is updated in qh_completions(). Update the QH
140 * overlay here.
141 */
142 if (qh->hw->hw_token & ACTIVE_BIT(ehci)) {
143 qh->hw->hw_qtd_next = qtd->hw_next;
144 if (qh->should_be_inactive)
145 ehci_warn("qh %p should be inactive!\n", qh);
146 } else {
147 qh_update(ehci, qh, qtd);
148 }
149 qh->should_be_inactive = 0;
150 }
151
152 /*-------------------------------------------------------------------------*/
153
154 static void qh_link_async(struct ehci_hcd *ehci, struct ehci_qh *qh);
155
156 //static void ehci_clear_tt_buffer_complete(struct usb_hcd *hcd,
ehci_clear_tt_buffer_complete(struct hc_gen_dev * hcd,struct usb_host_virt_endpoint * ep)157 static void ehci_clear_tt_buffer_complete(struct hc_gen_dev *hcd,
158 struct usb_host_virt_endpoint *ep)
159 {
160 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
161 struct ehci_qh *qh = ep->hcpriv;
162 unsigned long flags;
163
164 flags = hal_spin_lock_irqsave(&ehci->lock);
165 qh->clearing_tt = 0;
166 if (qh->qh_state == QH_STATE_IDLE && !list_empty(&qh->qtd_list)
167 && ehci->rh_state == EHCI_RH_RUNNING)
168 qh_link_async(ehci, qh);
169 hal_spin_unlock_irqrestore(&ehci->lock, flags);
170 }
171
172 //static void ehci_clear_tt_buffer(struct ehci_hcd *ehci, struct ehci_qh *qh,
173 // struct urb *urb, u32 token)
174 //{
175 //
176 // /* If an async split transaction gets an error or is unlinked,
177 // * the TT buffer may be left in an indeterminate state. We
178 // * have to clear the TT buffer.
179 // *
180 // * Note: this routine is never called for Isochronous transfers.
181 // */
182 // if (urb->dev->tt && !usb_pipeint(urb->pipe) && !qh->clearing_tt) {
183 ////#ifdef CONFIG_DYNAMIC_DEBUG
184 //// struct usb_device *tt = urb->dev->tt->hub;
185 //// dev_dbg(&tt->dev,
186 //// "clear tt buffer port %d, a%d ep%d t%08x\n",
187 //// urb->dev->ttport, urb->dev->devnum,
188 //// usb_pipeendpoint(urb->pipe), token);
189 ////#endif /* CONFIG_DYNAMIC_DEBUG */
190 // if (!ehci_is_TDI(ehci)
191 // || urb->dev->tt->hub !=
192 // ehci_to_hcd(ehci)->self.root_hub) {
193 // if (usb_hub_clear_tt_buffer(urb) == 0)
194 // qh->clearing_tt = 1;
195 // } else {
196 //
197 // /* REVISIT ARC-derived cores don't clear the root
198 // * hub TT buffer in this way...
199 // */
200 // }
201 // }
202 //}
203
qtd_copy_status(struct ehci_hcd * ehci,struct urb * urb,size_t length,u32 token)204 static int qtd_copy_status (
205 struct ehci_hcd *ehci,
206 struct urb *urb,
207 size_t length,
208 u32 token
209 )
210 {
211 int status = -EINPROGRESS;
212
213 /* count IN/OUT bytes, not SETUP (even short packets) */
214 if (QTD_PID (token) != 2)
215 urb->actual_length += length - QTD_LENGTH (token);
216
217 /* don't modify error codes */
218 //if (unlikely(urb->unlinked))
219 // return status;
220
221 /* force cleanup after short read; not always an error */
222 //if (unlikely (IS_SHORT_READ (token)))
223 // status = -EREMOTEIO;
224
225 /* serious "can't proceed" faults reported by the hardware */
226 if (token & QTD_STS_HALT) {
227 if (token & QTD_STS_BABBLE) {
228 /* FIXME "must" disable babbling device's port too */
229 status = -EOVERFLOW;
230 /* CERR nonzero + halt --> stall */
231 } else if (QTD_CERR(token)) {
232 status = -EPIPE;
233
234 /* In theory, more than one of the following bits can be set
235 * since they are sticky and the transaction is retried.
236 * Which to test first is rather arbitrary.
237 */
238 } else if (token & QTD_STS_MMF) {
239 /* fs/ls interrupt xfer missed the complete-split */
240 status = -EPROTO;
241 } else if (token & QTD_STS_DBE) {
242 status = (QTD_PID (token) == 1) /* IN ? */
243 ? -ENOSR /* hc couldn't read data */
244 : -ECOMM; /* hc couldn't write data */
245 } else if (token & QTD_STS_XACT) {
246 /* timeout, bad CRC, wrong PID, etc */
247 //ehci_dbg("devpath %s ep%d%s 3strikes\n",
248 // urb->dev->devpath,
249 // usb_pipeendpoint(urb->pipe),
250 // usb_pipein(urb->pipe) ? "in" : "out");
251 status = -EPROTO;
252 } else { /* unknown */
253 status = -EPROTO;
254 }
255 }
256
257 return status;
258 }
259
260 static void
ehci_urb_done(struct ehci_hcd * ehci,struct urb * urb,int status)261 ehci_urb_done(struct ehci_hcd *ehci, struct urb *urb, int status)
262 {
263 if (usb_pipetype(urb->pipe) == PIPE_INTERRUPT) {
264 /* ... update hc-wide periodic stats */
265 ehci_to_hcd(ehci)->self.bandwidth_int_reqs--;
266 }
267
268 if (unlikely(urb->unlinked)) {
269 COUNT(ehci->stats.unlink);
270 } else {
271 /* report non-error and short read status as zero */
272 if (status == -EINPROGRESS || status == -EREMOTEIO)
273 status = 0;
274 COUNT(ehci->stats.complete);
275 }
276
277 //#ifdef EHCI_URB_TRACE
278 // ehci_dbg (ehci,
279 // "%s %s urb %p ep%d%s status %d len %d/%d\n",
280 // __func__, urb->dev->devpath, urb,
281 // usb_pipeendpoint (urb->pipe),
282 // usb_pipein (urb->pipe) ? "in" : "out",
283 // status,
284 // urb->actual_length, urb->transfer_buffer_length);
285 //#endif
286
287 // usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
288 //usb_hcd_giveback_urb(ehci_to_hcd(ehci), urb, status);
289
290 if (urb->status == -EINPROGRESS)
291 {
292 urb->status = status;
293 }
294
295 urb->hcpriv = NULL;
296
297 usb_hcd_giveback_urb(ehci_to_hcd(ehci), urb);
298 }
299
300 static int qh_schedule (struct ehci_hcd *ehci, struct ehci_qh *qh);
301
302 /*
303 * Process and free completed qtds for a qh, returning URBs to drivers.
304 * Chases up to qh->hw_current. Returns nonzero if the caller should
305 * unlink qh.
306 */
307 // qh_completions()中通过对qh下链接的qtd进行逐个遍历，来判断传输的情况
qh_completions(struct ehci_hcd * ehci,struct ehci_qh * qh)308 static unsigned qh_completions(struct ehci_hcd *ehci, struct ehci_qh *qh)
309 {
310 struct ehci_qtd *last, *end = qh->dummy;
311 struct list_head *entry, *tmp;
312 int last_status;
313 int stopped;
314 u8 state;
315 struct ehci_qh_hw *hw = qh->hw;
316
317 /* completions (or tasks on other cpus) must never clobber HALT
318 * till we've gone through and cleaned everything up, even when
319 * they add urbs to this qh's queue or mark them for unlinking.
320 *
321 * NOTE: unlinking expects to be done in queue order.
322 *
323 * It's a bug for qh->qh_state to be anything other than
324 * QH_STATE_IDLE, unless our caller is scan_async() or
325 * scan_intr().
326 */
327 state = qh->qh_state;
328 qh->qh_state = QH_STATE_COMPLETING;
329 stopped = (state == QH_STATE_IDLE);
330
331 rescan:
332 last = NULL;
333 last_status = -EINPROGRESS;
334 qh->dequeue_during_giveback = 0;
335
336 /* remove de-activated QTDs from front of queue.
337 * after faults (including short reads), cleanup this urb
338 * then let the queue advance.
339 * if queue is stopped, handles unlinks.
340 */
341 // list_for_each_safe逐个的把qh上的qtd取出放在指针entry中，
342 // list_for_each_safe的特点是可以中途删除entry，通过指针tmp去找到下一个entry
343 //该语句实际上是一个for循环
344 list_for_each_safe (entry, tmp, &qh->qtd_list) {
345 struct ehci_qtd *qtd;
346 struct urb *urb;
347 u32 token = 0;
348
349 //printf("\n");
350 // 找到对应的qtd内存地址
351 qtd = list_entry(entry, struct ehci_qtd, qtd_list);
352 urb = qtd->urb;
353
354 /* clean up any state from previous QTD ...*/
355 //last初始值是NULL，第一次不执行，跳过if
356 // 当再一次执行到此处时，如果前一次的处理中有qtd是执行完传输的（包括传输出错），
357 // last此时就会指向了前一个qtd，并在if语句中的ehci_qtd_free()函数中把分配的qtd空间释放掉
358 if (last) {
359 // 一个qtd链表中的urb指针的指向都是相同的，除了最末这一个dummy qtd，
360 // 所以在遍历到最后的qtd时“last->urb != urb”满足
361 if (likely(last->urb != urb)) {
362 // ehci_urb_done()要做的一件事是回调urb->complete()函数指针，
363 // 从而使控制权回到USB device Driver中，这就是我们填充一个urb的回调函数的触发处
364 ehci_urb_done(ehci, last->urb, last_status);
365 last_status = -EINPROGRESS;
366 }
367 ehci_qtd_free (ehci, last);
368 // list_add_tail(&(last->qtd_list), &(ehci->wait_free_list));
369 // hal_log_info("\033[41m ADD : last = 0x%x \033[0m", last);
370 last = NULL;
371 }
372
373 /* ignore urbs submitted during completions we reported */
374 // 判断遍历到最后的dummy qtd，就跳出循环，表明整个qtd链表已被处理完了
375 if (qtd == end) {
376 break;
377 }
378
379 /* hardware copies qtd out of qh overlay */
380 //rmb ();
381 // HC在处理完一个qtd后，反映处理结果的值会回写到当前qtd的token字段中，
382 // HCD读取这个token的Status值后，可以获知HC的传输情况
383 hal_dcache_invalidate((unsigned long)&(((struct ehci_qtd *)(qtd->qtd_dma))->hw_token), sizeof(uint32_t));
384 token = hc32_to_cpu(ehci, qtd->hw_token);
385 EHCI_DEBUG_PRINTF("token = 0x%lx", token);
386
387 /* always clean up qtds the hc de-activated */
388 retry_xacterr:
389 if ((token & QTD_STS_ACTIVE) == 0) {
390 // 传输完成
391
392 /* Report Data Buffer Error: non-fatal but useful */
393 // 在EHCI SPEC里说，不被视作传输错误，会强制endpoint重发一次，所以代码也只是做了打印
394 if (token & QTD_STS_DBE)
395 {
396 EHCI_DEBUG_PRINTF("detected DataBufferErr for urb %p ep%d%s len %d, qtd %p [qh %p]",
397 urb,
398 usb_endpoint_num(&urb->ep->desc),
399 usb_endpoint_dir_in(&urb->ep->desc) ? "in" : "out",
400 urb->transfer_buffer_length,
401 qtd,
402 qh);
403 }
404 /* on STALL, error, and short reads this urb must
405 * complete and all its qtds must be recycled.
406 */
407 if ((token & QTD_STS_HALT) != 0) {
408 // 表明当前qtd的传输出现了错误，而且与该endpoint的传输都被停掉
409 EHCI_DEBUG_PRINTF("error halt");
410 /* retry transaction errors until we
411 * reach the software xacterr limit
412 */
413 // QTD_STS_XACT代表HC没有收到device发回的有效应答包
414 if ((token & QTD_STS_XACT) &&
415 QTD_CERR(token) == 0 &&
416 ++qh->xacterrs < QH_XACTERR_MAX &&
417 !urb->unlinked) {
418 EHCI_DEBUG_PRINTF("detected XactErr len %zu/%zu retry %d",
419 qtd->length - QTD_LENGTH(token), qtd->length, qh->xacterrs);
420
421 /* reset the token in the qtd and the
422 * qh overlay (which still contains
423 * the qtd) so that we pick up from
424 * where we left off
425 */
426 // 出现这样的错误HCD的处理方式是，
427 // 由软件把Halted位清零，
428 // token[11:10] CERR位设为0x3，
429 // Active位置1再次使能该qtd，
430 // 让HC重新传输这个qtd
431 token &= ~QTD_STS_HALT;
432 token |= QTD_STS_ACTIVE |
433 (EHCI_TUNE_CERR << 10);
434 qtd->hw_token = cpu_to_hc32(ehci, token);
435 //wmb();
436 hw->hw_token = cpu_to_hc32(ehci, token);
437
438 hal_dcache_clean_invalidate((unsigned long)&(((struct ehci_qtd *)(qtd->qtd_dma))->hw_token), sizeof(uint32_t));
439 hal_dcache_clean_invalidate((unsigned long)&(((struct ehci_qh_hw *)(qh->qh_dma))->hw_token), sizeof(uint32_t));
440
441 // 重复以上动作，直到传输成功或超时为止
442 goto retry_xacterr;
443 }
444 stopped = 1;
445 qh->unlink_reason |= QH_UNLINK_HALTED;
446
447 /* magic dummy for some short reads; qh won't advance.
448 * that silicon quirk can kick in with this dummy too.
449 *
450 * other short reads won't stop the queue, including
451 * control transfers (status stage handles that) or
452 * most other single-qtd reads ... the queue stops if
453 * URB_SHORT_NOT_OK was set so the driver submitting
454 * the urbs could clean it up.
455 */
456 } else if (IS_SHORT_READ (token)
457 && !(qtd->hw_alt_next
458 & EHCI_LIST_END(ehci))) {
459 EHCI_DEBUG_PRINTF("short reads");
460 stopped = 1;
461 qh->unlink_reason |= QH_UNLINK_SHORT_READ;
462 }
463
464 /* stop scanning when we reach qtds the hc is using */
465 } else if (!stopped
466 && ehci->rh_state >= EHCI_RH_RUNNING) {
467 EHCI_DEBUG_PRINTF("stop scanning");
468 break;
469
470 /* scan the whole queue for unlinks whenever it stops */
471 } else {
472 EHCI_DEBUG_PRINTF("stopped");
473 stopped = 1;
474
475 /* cancel everything if we halt, suspend, etc */
476 if (ehci->rh_state < EHCI_RH_RUNNING) {
477 last_status = -ESHUTDOWN;
478 qh->unlink_reason |= QH_UNLINK_SHUTDOWN;
479 }
480
481 /* this qtd is active; skip it unless a previous qtd
482 * for its urb faulted, or its urb was canceled.
483 */
484 else if (last_status == -EINPROGRESS && !urb->unlinked) {
485 // else if (last_status == -EINPROGRESS) {
486 continue;
487 }
488
489 /*
490 * If this was the active qtd when the qh was unlinked
491 * and the overlay's token is active, then the overlay
492 * hasn't been written back to the qtd yet so use its
493 * token instead of the qtd's. After the qtd is
494 * processed and removed, the overlay won't be valid
495 * any more.
496 */
497 if (state == QH_STATE_IDLE &&
498 qh->qtd_list.next == &qtd->qtd_list &&
499 (hw->hw_token & ACTIVE_BIT(ehci))) {
500 token = hc32_to_cpu(ehci, hw->hw_token);
501 hw->hw_token &= ~ACTIVE_BIT(ehci);
502 qh->should_be_inactive = 1;
503
504 /* An unlink may leave an incomplete
505 * async transaction in the TT buffer.
506 * We have to clear it.
507 */
508 //ehci_clear_tt_buffer(ehci, qh, urb, token);
509 }
510 }
511
512 /* unless we already know the urb's status, collect qtd status
513 * and update count of bytes transferred. in common short read
514 * cases with only one data qtd (including control transfers),
515 * queue processing won't halt. but with two or more qtds (for
516 * example, with a 32 KB transfer), when the first qtd gets a
517 * short read the second must be removed by hand.
518 */
519 if (last_status == -EINPROGRESS) {
520 // 读取状态
521 last_status = qtd_copy_status(ehci, urb,
522 qtd->length, token);
523 if (last_status == -EREMOTEIO
524 && (qtd->hw_alt_next
525 & EHCI_LIST_END(ehci))) {
526 last_status = -EINPROGRESS;
527 }
528 /* As part of low/full-speed endpoint-halt processing
529 * we must clear the TT buffer (11.17.5).
530 */
531 //if (unlikely(last_status != -EINPROGRESS &&
532 // last_status != -EREMOTEIO)) {
533 // /* The TT's in some hubs malfunction when they
534 // * receive this request following a STALL (they
535 // * stop sending isochronous packets). Since a
536 // * STALL can't leave the TT buffer in a busy
537 // * state (if you believe Figures 11-48 - 11-51
538 // * in the USB 2.0 spec), we won't clear the TT
539 // * buffer in this case. Strictly speaking this
540 // * is a violation of the spec.
541 // */
542 // if (last_status != -EPIPE)
543 // ehci_clear_tt_buffer(ehci, qh, urb,
544 // token);
545 //}
546 }
547
548 /* if we're removing something not at the queue head,
549 * patch the hardware queue pointer.
550 */
551 //如果是qtd链表的首个元素，则qtd->qtd_list.prev == &qh->qtd_list
552 //如果不是首元素，则需要先解链再释放，如是首元素，则不必
553 if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {
554 //找到上一个qtd的地址
555 last = list_entry (qtd->qtd_list.prev,
556 struct ehci_qtd, qtd_list);
557 //将上一个qtd的next与本qtd的next链接，即，将本qtd从链表中解链
558 last->hw_next = qtd->hw_next;
559
560 hal_dcache_clean_invalidate((unsigned long)&(((struct ehci_qtd *)(last->qtd_dma))->hw_next), sizeof(uint32_t));
561 hal_dcache_clean_invalidate((unsigned long)&(((struct ehci_qtd *)(qtd->qtd_dma))->hw_next), sizeof(uint32_t));
562 }
563
564 /* remove qtd; it's recycled after possible urb completion */
565 //释放
566 list_del (&qtd->qtd_list);
567 //记录到last里，下一次循环时真正回收qtd
568 last = qtd;
569
570 /* reinit the xacterr counter for the next qtd */
571 qh->xacterrs = 0;
572 }//end of list_for_each_safe(entry, tmp, &qh->qtd_list)
573
574 /* last urb's completion might still need calling */
575 // 如果指针last非空，那么一定是指向一个qtd链表队列的末尾处（非dummy qtd）
576 if (last != NULL) {
577 ehci_urb_done(ehci, last->urb, last_status);
578 ehci_qtd_free(ehci, last);
579 // list_add_tail(&(last->qtd_list), &(ehci->wait_free_list));
580 // hal_log_info("\033[41m ADD : last = 0x%x \033[0m", last);
581 }
582
583 /* Do we need to rescan for URBs dequeued during a giveback? */
584 if (unlikely(qh->dequeue_during_giveback)) {
585 /* If the QH is already unlinked, do the rescan now. */
586 if (state == QH_STATE_IDLE) {
587 EHCI_DEBUG_PRINTF("goto rescan");
588 goto rescan;
589 }
590
591 /* Otherwise the caller must unlink the QH. */
592 }
593
594 /* restore original state; caller must unlink or relink */
595 qh->qh_state = state;
596
597 /* be sure the hardware's done with the qh before refreshing
598 * it after fault cleanup, or recovering from silicon wrongly
599 * overlaying the dummy qtd (which reduces DMA chatter).
600 *
601 * We won't refresh a QH that's linked (after the HC
602 * stopped the queue). That avoids a race:
603 * - HC reads first part of QH;
604 * - CPU updates that first part and the token;
605 * - HC reads rest of that QH, including token
606 * Result: HC gets an inconsistent image, and then
607 * DMAs to/from the wrong memory (corrupting it).
608 *
609 * That should be rare for interrupt transfers,
610 * except maybe high bandwidth ...
611 */
612 if (stopped != 0 || hw->hw_qtd_next == EHCI_LIST_END(ehci)) {
613 qh->unlink_reason |= QH_UNLINK_DUMMY_OVERLAY;
614 }
615
616 EHCI_DEBUG_PRINTF("qh->unlink_reason = %u\n", qh->unlink_reason);
617 /* Let the caller know if the QH needs to be unlinked. */
618 return qh->unlink_reason;
619 }
620
621 /*-------------------------------------------------------------------------*/
622
623 // high bandwidth multiplier, as encoded in highspeed endpoint descriptors
624 #define hb_mult(wMaxPacketSize) (1 + (((wMaxPacketSize) >> 11) & 0x03))
625 // ... and packet size, for any kind of endpoint descriptor
626 #define max_packet(wMaxPacketSize) ((wMaxPacketSize) & 0x07ff)
627
628 /*
629 * reverse of qh_urb_transaction: free a list of TDs.
630 * used for cleanup after errors, before HC sees an URB's TDs.
631 */
qtd_list_free(struct ehci_hcd * ehci,struct urb * urb,struct list_head * qtd_list)632 static void qtd_list_free (
633 struct ehci_hcd *ehci,
634 struct urb *urb,
635 struct list_head *qtd_list
636 ) {
637 struct list_head *entry, *temp;
638
639 list_for_each_safe (entry, temp, qtd_list) {
640 struct ehci_qtd *qtd;
641
642 qtd = list_entry (entry, struct ehci_qtd, qtd_list);
643 list_del (&qtd->qtd_list);
644 ehci_qtd_free (ehci, qtd);
645 }
646 }
647
648 /*
649 * create a list of filled qtds for this URB; won't link into qh.
650 * 为URB创建并填充qtd列表，但是并未加到qh中
651 * 一次USB的传输请求是由usb_submit_urb()提交下来的，要传输相关的数据、地址等信息都放在URB中
652 * qh_urb_transaction()函数就是对URB携带的信息整合到EHCI能识别的数据结构中，即构造相应的qTD
653 */
654 static struct list_head *
qh_urb_transaction(struct ehci_hcd * ehci,struct urb * urb,struct list_head * head,gfp_t flags)655 qh_urb_transaction (
656 struct ehci_hcd *ehci,
657 struct urb *urb,
658 struct list_head *head,
659 gfp_t flags
660 ) {
661 struct ehci_qtd *qtd, *qtd_prev;
662 dma_addr_t buf;
663 int len, this_sg_len, maxpacket;
664 int is_input;
665 u32 token;
666 int i = 0;
667 //struct scatterlist *sg;
668
669 /*
670 * URBs map to sequences of QTDs: one logical transaction
671 */
672 qtd = ehci_qtd_alloc (ehci, flags);
673 if (!qtd)
674 return NULL;
675 list_add_tail (&qtd->qtd_list, head);
676 qtd->urb = urb;
677
678 token = QTD_STS_ACTIVE;//使能该qtd
679 token |= (EHCI_TUNE_CERR << 10);
680 /* for split transactions, SplitXState initialized to zero */
681
682 len = urb->transfer_buffer_length;
683 is_input = usb_pipein (urb->pipe);
684 if (usb_pipecontrol (urb->pipe)) {
685 /* SETUP pid */
686 // 在此处将urb对应的数据包地址信息分配到qtd的pointer中，并返回长度
687 qtd_fill(ehci, qtd, urb->setup_dma,
688 sizeof (struct usb_ctrlrequest),
689 token | (2 /* "setup" */ << 8), 8);
690
691 /* ... and always at least one more pid */
692 token ^= QTD_TOGGLE;
693 //用qtd_prev指向填充过的qtd，再申请一个空的qtd
694 qtd_prev = qtd;
695 qtd = ehci_qtd_alloc (ehci, flags);
696 if (!qtd)
697 goto cleanup;
698 qtd->urb = urb;
699
700 // 将新的qtd联入队列
701 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
702 list_add_tail (&qtd->qtd_list, head);
703
704 /* for zero length DATA stages, STATUS is always IN */
705 // 为0说明是仅用于control的命令传输，没有数据
706 if (len == 0)
707 token |= (1 /* "in" */ << 8);
708 }
709
710 /*
711 * data transfer stage: buffer setup
712 */
713 //i = urb->num_mapped_sgs;
714 //if (len > 0 && i > 0) {
715 // sg = urb->sg;
716 // buf = sg_dma_address(sg);
717
718 // /* urb->transfer_buffer_length may be smaller than the
719 // * size of the scatterlist (or vice versa)
720 // */
721 // this_sg_len = min_t(int, sg_dma_len(sg), len);
722 //} else {
723 //sg = NULL;
724 buf = urb->transfer_dma;
725 this_sg_len = len;
726 //}
727
728 if (is_input)
729 token |= (1 /* "in" */ << 8);
730 /* else it's already initted to "out" pid (0 << 8) */
731
732 maxpacket = max_packet(usb_maxpacket(urb->dev, urb->pipe, !is_input));
733
734 /*
735 * buffer gets wrapped in one or more qtds;
736 * last one may be "short" (including zero len)
737 * and may serve as a control status ack
738 */
739 for (;;) {
740 int this_qtd_len;
741
742 this_qtd_len = qtd_fill(ehci, qtd, buf, this_sg_len, token,
743 maxpacket);
744 this_sg_len -= this_qtd_len;
745 len -= this_qtd_len;
746 buf += this_qtd_len;
747
748 /*
749 * short reads advance to a "magic" dummy instead of the next
750 * qtd ... that forces the queue to stop, for manual cleanup.
751 * (this will usually be overridden later.)
752 */
753 if (is_input)
754 qtd->hw_alt_next = ehci->async->hw->hw_alt_next;
755
756 /* qh makes control packets use qtd toggle; maybe switch it */
757 if ((maxpacket & (this_qtd_len + (maxpacket - 1))) == 0)
758 token ^= QTD_TOGGLE;
759
760 if (this_sg_len <= 0) {
761 if (--i <= 0 || len <= 0)
762 break;
763 // sg = sg_next(sg);
764 // buf = sg_dma_address(sg);
765 // this_sg_len = min_t(int, sg_dma_len(sg), len);
766 }
767
768 qtd_prev = qtd;
769 qtd = ehci_qtd_alloc (ehci, flags);
770 if (!qtd)
771 goto cleanup;
772 qtd->urb = urb;
773 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
774 list_add_tail (&qtd->qtd_list, head);
775 }
776
777 /*
778 * unless the caller requires manual cleanup after short reads,
779 * have the alt_next mechanism keep the queue running after the
780 * last data qtd (the only one, for control and most other cases).
781 */
782 if ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0
783 || usb_pipecontrol (urb->pipe))
784 qtd->hw_alt_next = EHCI_LIST_END(ehci);
785
786 /*
787 * control requests may need a terminating data "status" ack;
788 * other OUT ones may need a terminating short packet
789 * (zero length).
790 */
791 // 对urb中transfer_buffer_length非零，即涉及数据传输，且传输类型为Control或者是传输方向为OUT，就增加一个qtd作为结束，
792 // 该qtd要传输的数据长度为零。并把最后一个qtd的token中IOC位置1，表示在完成qtd的传输后，在下一个中断周期产生一个中断
793 if (urb->transfer_buffer_length != 0) {
794 int one_more = 0;
795
796 if (usb_pipecontrol (urb->pipe)) {
797 one_more = 1;
798 token ^= 0x0100; /* "in" <--> "out" */
799 token |= QTD_TOGGLE; /* force DATA1 */
800 //printf("[%s %d] token = 0x%lx\n", __func__, __LINE__, token);
801 } else if (usb_pipeout(urb->pipe)
802 && (urb->transfer_flags & URB_ZERO_PACKET)
803 && !(urb->transfer_buffer_length % maxpacket)) {
804 one_more = 1;
805 }
806 if (one_more) {
807 qtd_prev = qtd;
808 qtd = ehci_qtd_alloc (ehci, flags);
809 if (!qtd)
810 goto cleanup;
811 qtd->urb = urb;
812 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
813 list_add_tail (&qtd->qtd_list, head);
814
815 /* never any data in such packets */
816 qtd_fill(ehci, qtd, 0, 0, token, 0);
817 }
818 }
819
820 /* by default, enable interrupt on urb completion */
821 if (!(urb->transfer_flags & URB_NO_INTERRUPT))
822 qtd->hw_token |= cpu_to_hc32(ehci, QTD_IOC);
823 return head;
824
825 cleanup:
826 qtd_list_free (ehci, urb, head);
827 return NULL;
828 }
829
830 /*-------------------------------------------------------------------------*/
831
832 // Would be best to create all qh's from config descriptors,
833 // when each interface/altsetting is established. Unlink
834 // any previous qh and cancel its urbs first; endpoints are
835 // implicitly reset then (data toggle too).
836 // That'd mean updating how usbcore talks to HCDs. (2.7?)
837
838
839 /*
840 * Each QH holds a qtd list; a QH is used for everything except iso.
841 *
842 * For interrupt urbs, the scheduler must set the microframe scheduling
843 * mask(s) each time the QH gets scheduled. For highspeed, that's
844 * just one microframe in the s-mask. For split interrupt transactions
845 * there are additional complications: c-mask, maybe FSTNs.
846 */
847 static struct ehci_qh *
qh_make(struct ehci_hcd * ehci,struct urb * urb,gfp_t flags)848 qh_make (
849 struct ehci_hcd *ehci,
850 struct urb *urb,
851 gfp_t flags
852 ) {
853 struct ehci_qh *qh = ehci_qh_alloc (ehci);
854 u32 info1 = 0, info2 = 0;
855 int is_input, type;
856 int maxp = 0;
857 //struct usb_tt *tt = urb->dev->tt;
858 struct ehci_qh_hw *hw;
859
860 if (!qh)
861 return qh;
862
863 /*
864 * init endpoint/device data for this QH
865 */
866 info1 |= usb_pipeendpoint (urb->pipe) << 8;
867 info1 |= usb_pipedevice (urb->pipe) << 0;
868
869 is_input = usb_pipein (urb->pipe);
870 type = usb_pipetype (urb->pipe);
871 maxp = usb_maxpacket (urb->dev, urb->pipe, !is_input);
872
873 /* 1024 byte maxpacket is a hardware ceiling. High bandwidth
874 * acts like up to 3KB, but is built from smaller packets.
875 */
876 if (max_packet(maxp) > 1024) {
877 ehci_dbg("bogus qh maxpacket %d\n", max_packet(maxp));
878 goto done;
879 }
880
881 /* Compute interrupt scheduling parameters just once, and save.
882 * - allowing for high bandwidth, how many nsec/uframe are used?
883 * - split transactions need a second CSPLIT uframe; same question
884 * - splits also need a schedule gap (for full/low speed I/O)
885 * - qh has a polling interval
886 *
887 * For control/bulk requests, the HC or TT handles these.
888 */
889 if (type == PIPE_INTERRUPT) {
890 unsigned tmp;
891
892 //qh->ps.usecs = NS_TO_US(usb_calc_bus_time(USB_SPEED_HIGH,
893 // is_input, 0,
894 // hb_mult(maxp) * max_packet(maxp)));
895 qh->ps.phase = NO_FRAME;
896
897 if (urb->dev->speed == USB_SPEED_HIGH) {
898 qh->ps.c_usecs = 0;
899 qh->gap_uf = 0;
900
901 if (urb->interval > 1 && urb->interval < 8) {
902 /* NOTE interval 2 or 4 uframes could work.
903 * But interval 1 scheduling is simpler, and
904 * includes high bandwidth.
905 */
906 urb->interval = 1;
907 } else if (urb->interval > ehci->periodic_size << 3) {
908 urb->interval = ehci->periodic_size << 3;
909 }
910 qh->ps.period = urb->interval >> 3;
911
912 /* period for bandwidth allocation */
913 tmp = min(EHCI_BANDWIDTH_SIZE,
914 1 << (urb->ep->desc.bInterval - 1));
915
916 /* Allow urb->interval to override */
917 qh->ps.bw_uperiod = min(tmp, (unsigned)urb->interval);
918 qh->ps.bw_period = qh->ps.bw_uperiod >> 3;
919 } else {
920 int think_time;
921
922 /* gap is f(FS/LS transfer times) */
923 //qh->gap_uf = 1 + usb_calc_bus_time (urb->dev->speed,
924 // is_input, 0, maxp) / (125 * 1000);
925
926 /* FIXME this just approximates SPLIT/CSPLIT times */
927 if (is_input) { // SPLIT, gap, CSPLIT+DATA
928 //qh->ps.c_usecs = qh->ps.usecs + HS_USECS(0);
929 //qh->ps.usecs = HS_USECS(1);
930 } else { // SPLIT+DATA, gap, CSPLIT
931 //qh->ps.usecs += HS_USECS(1);
932 //qh->ps.c_usecs = HS_USECS(0);
933 }
934
935 //think_time = tt ? tt->think_time : 0;
936 //qh->ps.tt_usecs = NS_TO_US(think_time +
937 // usb_calc_bus_time (urb->dev->speed,
938 // is_input, 0, max_packet (maxp)));
939 if (urb->interval > ehci->periodic_size)
940 urb->interval = ehci->periodic_size;
941 qh->ps.period = urb->interval;
942
943 /* period for bandwidth allocation */
944 tmp = min(EHCI_BANDWIDTH_FRAMES,
945 (unsigned)(urb->ep->desc.bInterval));
946 //tmp = rounddown_pow_of_two(tmp);
947
948 /* Allow urb->interval to override */
949 qh->ps.bw_period = min((unsigned)tmp, (unsigned)(urb->interval));
950 qh->ps.bw_uperiod = qh->ps.bw_period << 3;
951 }
952 }
953
954 /* support for tt scheduling, and access to toggles */
955 qh->ps.udev = urb->dev;
956 qh->ps.ep = urb->ep;
957
958 /* using TT? */
959 switch (urb->dev->speed) {
960 case USB_SPEED_LOW:
961 info1 |= QH_LOW_SPEED;
962 /* FALL THROUGH */
963
964 case USB_SPEED_FULL:
965 /* EPS 0 means "full" */
966 if (type != PIPE_INTERRUPT)
967 info1 |= (EHCI_TUNE_RL_TT << 28);
968 if (type == PIPE_CONTROL) {
969 info1 |= QH_CONTROL_EP; /* for TT */
970 info1 |= QH_TOGGLE_CTL; /* toggle from qtd */
971 }
972 info1 |= maxp << 16;
973
974 info2 |= (EHCI_TUNE_MULT_TT << 30);
975
976 /* Some Freescale processors have an erratum in which the
977 * port number in the queue head was 0..N-1 instead of 1..N.
978 */
979 if (ehci_has_fsl_portno_bug(ehci))
980 info2 |= (urb->dev->ttport-1) << 23;
981 else
982 info2 |= urb->dev->ttport << 23;
983
984 /* set the address of the TT; for TDI's integrated
985 * root hub tt, leave it zeroed.
986 */
987 //if (tt && tt->hub != ehci_to_hcd(ehci)->self.root_hub)
988 // info2 |= tt->hub->devnum << 16;
989
990 /* NOTE: if (PIPE_INTERRUPT) { scheduler sets c-mask } */
991
992 break;
993
994 case USB_SPEED_HIGH: /* no TT involved */
995 info1 |= QH_HIGH_SPEED;
996 if (type == PIPE_CONTROL) {
997 info1 |= (EHCI_TUNE_RL_HS << 28);
998 info1 |= 64 << 16; /* usb2 fixed maxpacket */
999 info1 |= QH_TOGGLE_CTL; /* toggle from qtd */
1000 info2 |= (EHCI_TUNE_MULT_HS << 30);
1001 } else if (type == PIPE_BULK) {
1002 info1 |= (EHCI_TUNE_RL_HS << 28);
1003 /* The USB spec says that high speed bulk endpoints
1004 * always use 512 byte maxpacket. But some device
1005 * vendors decided to ignore that, and MSFT is happy
1006 * to help them do so. So now people expect to use
1007 * such nonconformant devices with Linux too; sigh.
1008 */
1009 info1 |= max_packet(maxp) << 16;
1010 info2 |= (EHCI_TUNE_MULT_HS << 30);
1011 } else { /* PIPE_INTERRUPT */
1012 info1 |= max_packet (maxp) << 16;
1013 info2 |= hb_mult (maxp) << 30;
1014 }
1015 break;
1016 default:
1017 ehci_dbg("bogus dev %p speed %d\n", urb->dev,
1018 urb->dev->speed);
1019 done:
1020 qh_destroy(ehci, qh);
1021 return NULL;
1022 }
1023
1024 /* NOTE: if (PIPE_INTERRUPT) { scheduler sets s-mask } */
1025
1026 /* init as live, toggle clear */
1027 qh->qh_state = QH_STATE_IDLE;
1028 hw = qh->hw;
1029 hw->hw_info1 = cpu_to_hc32(ehci, info1);
1030 hw->hw_info2 = cpu_to_hc32(ehci, info2);
1031 qh->is_out = !is_input;
1032 usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe), !is_input, 1);
1033 return qh;
1034 }
1035
1036 /*-------------------------------------------------------------------------*/
1037
enable_async(struct ehci_hcd * ehci)1038 static void enable_async(struct ehci_hcd *ehci)
1039 {
1040
1041 int cmd;
1042 int ret;
1043
1044 if (ehci->async_count++)
1045 return;
1046
1047 ///* Stop waiting to turn off the async schedule */
1048 ehci->enabled_hrtimer_events &= ~BIT(EHCI_HRTIMER_DISABLE_ASYNC);
1049
1050 ///* Don't start the schedule until ASS is 0 */
1051 hal_dcache_clean_all(); //akira 20202020
1052 hal_dcache_invalidate_all(); //akira 20202020
1053 ehci_poll_ASS(ehci);
1054 turn_on_io_watchdog(ehci);
1055 /*scan??*/
1056
1057 //akira???
1058 // /* need to flush Dcache? */
1059 // hal_dcache_clean_all();
1060
1061 // /* Enable async. schedule. */
1062 // cmd = ehci_readl(ehci, &ehci->regs->command);
1063 // cmd |= CMD_ASE;
1064 // ehci_writel(ehci, cmd, &ehci->regs->command);
1065
1066 // ret = ehci_handshake(ehci, (uint32_t *)&ehci->regs->status, STS_ASS, STS_ASS,
1067 // 100*1000);
1068 // if (ret < 0) {
1069 // hal_log_err("EHCI fail timeout STS_ASS set.\n");
1070 // return;
1071 // }
1072
1073 // if (ehci->isoc_count > 0 || (ehci->async_count + ehci->intr_count > 0))
1074 // ehci_work(ehci);
1075 }
1076
disable_async(struct ehci_hcd * ehci)1077 static void disable_async(struct ehci_hcd *ehci)
1078 {
1079 int cmd;
1080 int ret;
1081
1082 if (--ehci->async_count)
1083 return;
1084
1085 /* The async schedule and unlink lists are supposed to be empty */
1086 //WARN_ON(ehci->async->qh_next.qh || !list_empty(&ehci->async_unlink) ||
1087 // !list_empty(&ehci->async_idle));
1088
1089 ///* Don't turn off the schedule until ASS is 1 */
1090 hal_dcache_clean_all(); //akira 20202020
1091 hal_dcache_invalidate_all(); //akira 20202020
1092
1093 ehci_poll_ASS(ehci);
1094 // cmd = ehci_readl(ehci, &ehci->regs->command);
1095 // cmd &= ~CMD_ASE;
1096 // ehci_writel(ehci, cmd, &ehci->regs->command);
1097
1098 // ret = ehci_handshake(ehci, (uint32_t *)&ehci->regs->status, STS_ASS, 0,
1099 // 100*1000);
1100 // if (ret < 0) {
1101 // hal_log_err("EHCI fail timeout STS_ASS reset.\n");
1102 // return;
1103 // }
1104 }
1105
1106 /* move qh (and its qtds) onto async queue; maybe enable queue. */
1107
qh_link_async(struct ehci_hcd * ehci,struct ehci_qh * qh)1108 static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
1109 {
1110 uint32_t dma = QH_NEXT(ehci, qh->qh_dma);
1111 struct ehci_qh *head;
1112
1113 /* Don't link a QH if there's a Clear-TT-Buffer pending */
1114 //if (unlikely(qh->clearing_tt))
1115 // return;
1116
1117 //WARN_ON(qh->qh_state != QH_STATE_IDLE);
1118
1119 /* clear halt and/or toggle; and maybe recover from silicon quirk */
1120 qh_refresh(ehci, qh);
1121
1122 /* splice right after start */
1123 head = ehci->async;
1124 qh->qh_next = head->qh_next;
1125 qh->hw->hw_next = head->hw->hw_next;
1126
1127 head->qh_next.qh = qh;
1128 head->hw->hw_next = dma;
1129
1130 qh->qh_state = QH_STATE_LINKED;
1131 qh->xacterrs = 0;
1132 qh->unlink_reason = 0;
1133 /* qtd completions reported later by interrupt */
1134
1135 enable_async(ehci);
1136 }
1137
1138 /*-------------------------------------------------------------------------*/
1139
1140 /*
1141 * For control/bulk/interrupt, return QH with these TDs appended.
1142 * Allocates and initializes the QH if necessary.
1143 * Returns null if it can't allocate a QH it needs to.
1144 * If the QH has TDs (urbs) already, that's great.
1145 */
qh_append_tds(struct ehci_hcd * ehci,struct urb * urb,struct list_head * qtd_list,int epnum,void ** ptr)1146 static struct ehci_qh *qh_append_tds (
1147 struct ehci_hcd *ehci,
1148 struct urb *urb,
1149 struct list_head *qtd_list,
1150 int epnum,
1151 void **ptr
1152 )
1153 {
1154 struct ehci_qh *qh = NULL;
1155 uint32_t qh_addr_mask = cpu_to_hc32(ehci, 0x7f);
1156
1157 qh = (struct ehci_qh *) *ptr;
1158 if (unlikely (qh == NULL)) {
1159 /* can't sleep here, we have ehci->lock... */
1160 qh = qh_make (ehci, urb, 0);
1161 *ptr = qh;
1162 }
1163 if (qh != NULL) {
1164 struct ehci_qtd *qtd;
1165
1166 if (unlikely (list_empty (qtd_list)))
1167 qtd = NULL;
1168 else
1169 qtd = list_entry (qtd_list->next, struct ehci_qtd,
1170 qtd_list);
1171
1172 /* control qh may need patching ... */
1173 if (epnum == 0) {
1174
1175 /* usb_reset_device() briefly reverts to address 0 */
1176 if (usb_pipedevice (urb->pipe) == 0)
1177 qh->hw->hw_info1 &= ~qh_addr_mask;
1178 }
1179
1180 /* just one way to queue requests: swap with the dummy qtd.
1181 * only hc or qh_refresh() ever modify the overlay.
1182 */
1183 if (qtd != NULL) {
1184 struct ehci_qtd *dummy;
1185 dma_addr_t dma;
1186 uint32_t token;
1187
1188 /* to avoid racing the HC, use the dummy td instead of
1189 * the first td of our list (becomes new dummy). both
1190 * tds stay deactivated until we're done, when the
1191 * HC is allowed to fetch the old dummy (4.10.2).
1192 */
1193 token = qtd->hw_token;
1194 qtd->hw_token = HALT_BIT(ehci);
1195
1196 dummy = qh->dummy;
1197
1198 dma = dummy->qtd_dma;
1199 *dummy = *qtd;
1200 dummy->qtd_dma = dma;
1201
1202 list_del (&qtd->qtd_list);
1203 list_add (&dummy->qtd_list, qtd_list);
1204 list_splice_tail(qtd_list, &qh->qtd_list);
1205
1206 ehci_qtd_init(ehci, qtd, qtd->qtd_dma);
1207 qh->dummy = qtd;
1208
1209 /* hc must see the new dummy at list end */
1210 dma = qtd->qtd_dma;
1211 qtd = list_entry (qh->qtd_list.prev,
1212 struct ehci_qtd, qtd_list);
1213 qtd->hw_next = QTD_NEXT(ehci, dma);
1214
1215 /* let the hc process these next qtds */
1216 dummy->hw_token = token;
1217
1218 urb->hcpriv = qh;
1219 }
1220 }
1221 return qh;
1222 }
1223
1224 /*-------------------------------------------------------------------------*/
1225
1226 static int
submit_async(struct ehci_hcd * ehci,struct urb * urb,struct list_head * qtd_list,gfp_t mem_flags)1227 submit_async (
1228 struct ehci_hcd *ehci,
1229 struct urb *urb,
1230 struct list_head *qtd_list,
1231 gfp_t mem_flags
1232 ) {
1233 int epnum;
1234 unsigned long flags;
1235 struct ehci_qh *qh = NULL;
1236 int rc = 0;
1237
1238 epnum = urb->ep->desc.bEndpointAddress;
1239
1240 flags = hal_spin_lock_irqsave(&ehci->lock);
1241 //if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
1242 // rc = -ESHUTDOWN;
1243 // goto done;
1244 //}
1245 // rc = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
1246 // if (rc)
1247 // goto done;
1248
1249 qh = qh_append_tds(ehci, urb, qtd_list, epnum, &urb->ep->hcpriv);
1250 if (qh == NULL) {
1251 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
1252 rc = -ENOMEM;
1253 goto done;
1254 }
1255
1256 /* Control/bulk operations through TTs don't need scheduling,
1257 * the HC and TT handle it when the TT has a buffer ready.
1258 */
1259 if (qh->qh_state == QH_STATE_IDLE) {
1260 qh_link_async(ehci, qh);
1261 }
1262 done:
1263 hal_spin_unlock_irqrestore(&ehci->lock, flags);
1264 // qtd_list_free (ehci, urb, &(ehci->wait_free_list));
1265
1266 if (qh == NULL)
1267 qtd_list_free (ehci, urb, qtd_list);
1268 return rc;
1269 }
1270
single_unlink_async(struct ehci_hcd * ehci,struct ehci_qh * qh)1271 static void single_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh)
1272 {
1273 struct ehci_qh *prev;
1274
1275 /* Add to the end of the list of QHs waiting for the next IAAD */
1276 qh->qh_state = QH_STATE_UNLINK_WAIT;
1277 list_add_tail(&qh->unlink_node, &ehci->async_unlink);
1278
1279 /* Unlink it from the schedule */
1280 prev = ehci->async;
1281 while (prev->qh_next.qh != qh)
1282 prev = prev->qh_next.qh;
1283
1284 prev->hw->hw_next = qh->hw->hw_next;
1285 prev->qh_next = qh->qh_next;
1286 if (ehci->qh_scan_next == qh)
1287 ehci->qh_scan_next = qh->qh_next.qh;
1288 }
1289
start_iaa_cycle(struct ehci_hcd * ehci)1290 static void start_iaa_cycle(struct ehci_hcd *ehci)
1291 {
1292 /* If the controller isn't running, we don't have to wait for it */
1293 if (unlikely(ehci->rh_state < EHCI_RH_RUNNING)) {
1294 end_unlink_async(ehci);
1295
1296 /* Otherwise start a new IAA cycle if one isn't already running */
1297 } else if (ehci->rh_state == EHCI_RH_RUNNING &&
1298 !ehci->iaa_in_progress) {
1299
1300 /* Make sure the unlinks are all visible to the hardware */
1301 //wmb();
1302
1303 ehci_writel(ehci, ehci->command | CMD_IAAD,
1304 &ehci->regs->command);
1305 ehci_readl(ehci, &ehci->regs->command);
1306 ehci->iaa_in_progress = true;
1307 // ehci_enable_event(ehci, EHCI_HRTIMER_IAA_WATCHDOG, true);
1308 ehci_iaa_watchdog(ehci);
1309 }
1310 }
1311
end_iaa_cycle(struct ehci_hcd * ehci)1312 static void end_iaa_cycle(struct ehci_hcd *ehci)
1313 {
1314 if (ehci->has_synopsys_hc_bug)
1315 ehci_writel(ehci, (u32) ehci->async->qh_dma,
1316 &ehci->regs->async_next);
1317
1318 /* The current IAA cycle has ended */
1319 ehci->iaa_in_progress = false;
1320
1321 end_unlink_async(ehci);
1322 }
1323
1324 /* See if the async qh for the qtds being unlinked are now gone from the HC */
1325
end_unlink_async(struct ehci_hcd * ehci)1326 static void end_unlink_async(struct ehci_hcd *ehci)
1327 {
1328 struct ehci_qh *qh;
1329 bool early_exit;
1330
1331 if (list_empty(&ehci->async_unlink))
1332 return;
1333 qh = list_first_entry(&ehci->async_unlink, struct ehci_qh,
1334 unlink_node); /* QH whose IAA cycle just ended */
1335
1336 /*
1337 * If async_unlinking is set then this routine is already running,
1338 * either on the stack or on another CPU.
1339 */
1340 early_exit = ehci->async_unlinking;
1341
1342 /* If the controller isn't running, process all the waiting QHs */
1343 if (ehci->rh_state < EHCI_RH_RUNNING)
1344 list_splice_tail_init(&ehci->async_unlink, &ehci->async_idle);
1345
1346 /*
1347 * Intel (?) bug: The HC can write back the overlay region even
1348 * after the IAA interrupt occurs. In self-defense, always go
1349 * through two IAA cycles for each QH.
1350 */
1351 else if (qh->qh_state == QH_STATE_UNLINK) {
1352 /*
1353 * Second IAA cycle has finished. Process only the first
1354 * waiting QH (NVIDIA (?) bug).
1355 */
1356 list_move_tail(&qh->unlink_node, &ehci->async_idle);
1357 }
1358
1359 /*
1360 * AMD/ATI (?) bug: The HC can continue to use an active QH long
1361 * after the IAA interrupt occurs. To prevent problems, QHs that
1362 * may still be active will wait until 2 ms have passed with no
1363 * change to the hw_current and hw_token fields (this delay occurs
1364 * between the two IAA cycles).
1365 *
1366 * The EHCI spec (4.8.2) says that active QHs must not be removed
1367 * from the async schedule and recommends waiting until the QH
1368 * goes inactive. This is ridiculous because the QH will _never_
1369 * become inactive if the endpoint NAKs indefinitely.
1370 */
1371
1372 /* Some reasons for unlinking guarantee the QH can't be active */
1373 else if (qh->unlink_reason & (QH_UNLINK_HALTED |
1374 QH_UNLINK_SHORT_READ | QH_UNLINK_DUMMY_OVERLAY))
1375 goto DelayDone;
1376
1377 /* The QH can't be active if the queue was and still is empty... */
1378 else if ((qh->unlink_reason & QH_UNLINK_QUEUE_EMPTY) &&
1379 list_empty(&qh->qtd_list))
1380 goto DelayDone;
1381
1382 /* ... or if the QH has halted */
1383 else if (qh->hw->hw_token & cpu_to_hc32(ehci, QTD_STS_HALT))
1384 goto DelayDone;
1385
1386 /* Otherwise we have to wait until the QH stops changing */
1387 else {
1388 uint32_t qh_current, qh_token;
1389
1390 qh_current = qh->hw->hw_current;
1391 qh_token = qh->hw->hw_token;
1392 if (qh_current != ehci->old_current ||
1393 qh_token != ehci->old_token) {
1394 ehci->old_current = qh_current;
1395 ehci->old_token = qh_token;
1396 ehci_enable_event(ehci, EHCI_HRTIMER_ACTIVE_UNLINK, true);
1397 return;
1398 }
1399 DelayDone:
1400 qh->qh_state = QH_STATE_UNLINK;
1401 early_exit = true;
1402 }
1403 ehci->old_current = ~0; /* Prepare for next QH */
1404
1405 /* Start a new IAA cycle if any QHs are waiting for it */
1406 if (!list_empty(&ehci->async_unlink))
1407 start_iaa_cycle(ehci);
1408
1409 /*
1410 * Don't allow nesting or concurrent calls,
1411 * or wait for the second IAA cycle for the next QH.
1412 */
1413 if (early_exit)
1414 return;
1415
1416 /* Process the idle QHs */
1417 ehci->async_unlinking = true;
1418 while (!list_empty(&ehci->async_idle)) {
1419 qh = list_first_entry(&ehci->async_idle, struct ehci_qh,
1420 unlink_node);
1421 list_del(&qh->unlink_node);
1422
1423 qh->qh_state = QH_STATE_IDLE;
1424 qh->qh_next.qh = NULL;
1425
1426 if (!list_empty(&qh->qtd_list))
1427 qh_completions(ehci, qh);
1428 if (!list_empty(&qh->qtd_list) &&
1429 ehci->rh_state == EHCI_RH_RUNNING)
1430 qh_link_async(ehci, qh);
1431 disable_async(ehci);
1432 }
1433 ehci->async_unlinking = false;
1434 }
1435
1436 static void start_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh);
1437
unlink_empty_async(struct ehci_hcd * ehci)1438 static void unlink_empty_async(struct ehci_hcd *ehci)
1439 {
1440 struct ehci_qh *qh;
1441 struct ehci_qh *qh_to_unlink = NULL;
1442 int count = 0;
1443
1444 /* Find the last async QH which has been empty for a timer cycle */
1445 for (qh = ehci->async->qh_next.qh; qh; qh = qh->qh_next.qh) {
1446 if (list_empty(&qh->qtd_list) &&
1447 qh->qh_state == QH_STATE_LINKED) {
1448 ++count;
1449 if (qh->unlink_cycle != ehci->async_unlink_cycle)
1450 qh_to_unlink = qh;
1451 }
1452 }
1453
1454 /* If nothing else is being unlinked, unlink the last empty QH */
1455 if (list_empty(&ehci->async_unlink) && qh_to_unlink) {
1456 qh_to_unlink->unlink_reason |= QH_UNLINK_QUEUE_EMPTY;
1457 start_unlink_async(ehci, qh_to_unlink);
1458 --count;
1459 }
1460
1461 /* Other QHs will be handled later */
1462 if (count > 0) {
1463 // ehci_enable_event(ehci, EHCI_HRTIMER_ASYNC_UNLINKS, true);
1464 ++ehci->async_unlink_cycle;
1465 unlink_empty_async(ehci);
1466 }
1467 }
1468
1469 #ifdef CONFIG_PM
1470
1471 /* The root hub is suspended; unlink all the async QHs */
unlink_empty_async_suspended(struct ehci_hcd * ehci)1472 static void unlink_empty_async_suspended(struct ehci_hcd *ehci)
1473 {
1474 struct ehci_qh *qh;
1475
1476 while (ehci->async->qh_next.qh) {
1477 qh = ehci->async->qh_next.qh;
1478 WARN_ON(!list_empty(&qh->qtd_list));
1479 single_unlink_async(ehci, qh);
1480 }
1481 }
1482
1483 #endif
1484
1485 /* makes sure the async qh will become idle */
1486 /* caller must own ehci->lock */
1487
start_unlink_async(struct ehci_hcd * ehci,struct ehci_qh * qh)1488 static void start_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh)
1489 {
1490 /* If the QH isn't linked then there's nothing we can do. */
1491 if (qh->qh_state != QH_STATE_LINKED)
1492 return;
1493
1494 single_unlink_async(ehci, qh);
1495 start_iaa_cycle(ehci);
1496 }
1497
1498 /*-------------------------------------------------------------------------*/
1499 // scan_async()函数的工作就是去check传输的状况，并回收qtd
scan_async(struct ehci_hcd * ehci)1500 static void scan_async (struct ehci_hcd *ehci)
1501 {
1502 struct ehci_qh *qh;
1503 bool check_unlinks_later = false;
1504
1505 ehci->qh_scan_next = ehci->async->qh_next.qh;
1506 while (ehci->qh_scan_next) {
1507 qh = ehci->qh_scan_next;
1508 ehci->qh_scan_next = qh->qh_next.qh;
1509
1510 /* clean any finished work for this qh */
1511 if (!list_empty(&qh->qtd_list)) {
1512 int temp;
1513
1514 /*
1515 * Unlinks could happen here; completion reporting
1516 * drops the lock. That's why ehci->qh_scan_next
1517 * always holds the next qh to scan; if the next qh
1518 * gets unlinked then ehci->qh_scan_next is adjusted
1519 * in single_unlink_async().
1520 */
1521 temp = qh_completions(ehci, qh);
1522 if (temp) {
1523 start_unlink_async(ehci, qh);
1524 } else if (list_empty(&qh->qtd_list)
1525 && qh->qh_state == QH_STATE_LINKED) {
1526 qh->unlink_cycle = ehci->async_unlink_cycle;
1527 check_unlinks_later = true;
1528 }
1529 }
1530 }
1531
1532 /*
1533 * Unlink empty entries, reducing DMA usage as well
1534 * as HCD schedule-scanning costs. Delay for any qh
1535 * we just scanned, there's a not-unusual case that it
1536 * doesn't stay idle for long.
1537 */
1538 // if (check_unlinks_later && ehci->rh_state == EHCI_RH_RUNNING &&
1539 // !(ehci->enabled_hrtimer_events &
1540 // BIT(EHCI_HRTIMER_ASYNC_UNLINKS))) {
1541 // ehci_enable_event(ehci, EHCI_HRTIMER_ASYNC_UNLINKS, true);
1542 // ++ehci->async_unlink_cycle;
1543 // }
1544 if (check_unlinks_later && ehci->rh_state == EHCI_RH_RUNNING) {
1545 ++ehci->async_unlink_cycle;//akira 20202020
1546 unlink_empty_async(ehci);
1547 }
1548 }
1549