Commit | Line | Data |
---|---|---|
c0efd232 LP |
1 | /* |
2 | * uvc_queue.c -- USB Video Class driver - Buffers management | |
3 | * | |
11fc5baf LP |
4 | * Copyright (C) 2005-2010 |
5 | * Laurent Pinchart (laurent.pinchart@ideasonboard.com) | |
c0efd232 LP |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | */ | |
13 | ||
14 | #include <linux/kernel.h> | |
27ac792c | 15 | #include <linux/mm.h> |
c0efd232 LP |
16 | #include <linux/list.h> |
17 | #include <linux/module.h> | |
18 | #include <linux/usb.h> | |
19 | #include <linux/videodev2.h> | |
20 | #include <linux/vmalloc.h> | |
21 | #include <linux/wait.h> | |
22 | #include <asm/atomic.h> | |
23 | ||
24 | #include "uvcvideo.h" | |
25 | ||
26 | /* ------------------------------------------------------------------------ | |
27 | * Video buffers queue management. | |
28 | * | |
29 | * Video queues is initialized by uvc_queue_init(). The function performs | |
30 | * basic initialization of the uvc_video_queue struct and never fails. | |
31 | * | |
32 | * Video buffer allocation and freeing are performed by uvc_alloc_buffers and | |
33 | * uvc_free_buffers respectively. The former acquires the video queue lock, | |
34 | * while the later must be called with the lock held (so that allocation can | |
35 | * free previously allocated buffers). Trying to free buffers that are mapped | |
36 | * to user space will return -EBUSY. | |
37 | * | |
38 | * Video buffers are managed using two queues. However, unlike most USB video | |
2c2d264b LP |
39 | * drivers that use an in queue and an out queue, we use a main queue to hold |
40 | * all queued buffers (both 'empty' and 'done' buffers), and an irq queue to | |
41 | * hold empty buffers. This design (copied from video-buf) minimizes locking | |
42 | * in interrupt, as only one queue is shared between interrupt and user | |
43 | * contexts. | |
c0efd232 LP |
44 | * |
45 | * Use cases | |
46 | * --------- | |
47 | * | |
2c2d264b | 48 | * Unless stated otherwise, all operations that modify the irq buffers queue |
c0efd232 LP |
49 | * are protected by the irq spinlock. |
50 | * | |
51 | * 1. The user queues the buffers, starts streaming and dequeues a buffer. | |
52 | * | |
53 | * The buffers are added to the main and irq queues. Both operations are | |
2c2d264b | 54 | * protected by the queue lock, and the later is protected by the irq |
c0efd232 LP |
55 | * spinlock as well. |
56 | * | |
57 | * The completion handler fetches a buffer from the irq queue and fills it | |
58 | * with video data. If no buffer is available (irq queue empty), the handler | |
59 | * returns immediately. | |
60 | * | |
61 | * When the buffer is full, the completion handler removes it from the irq | |
d7c0d439 | 62 | * queue, marks it as done (UVC_BUF_STATE_DONE) and wakes its wait queue. |
c0efd232 | 63 | * At that point, any process waiting on the buffer will be woken up. If a |
d7c0d439 | 64 | * process tries to dequeue a buffer after it has been marked done, the |
c0efd232 LP |
65 | * dequeing will succeed immediately. |
66 | * | |
67 | * 2. Buffers are queued, user is waiting on a buffer and the device gets | |
68 | * disconnected. | |
69 | * | |
70 | * When the device is disconnected, the kernel calls the completion handler | |
71 | * with an appropriate status code. The handler marks all buffers in the | |
72 | * irq queue as being erroneous (UVC_BUF_STATE_ERROR) and wakes them up so | |
73 | * that any process waiting on a buffer gets woken up. | |
74 | * | |
75 | * Waking up up the first buffer on the irq list is not enough, as the | |
76 | * process waiting on the buffer might restart the dequeue operation | |
77 | * immediately. | |
78 | * | |
79 | */ | |
80 | ||
9bde9f26 LP |
81 | void uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type, |
82 | int drop_corrupted) | |
c0efd232 LP |
83 | { |
84 | mutex_init(&queue->mutex); | |
85 | spin_lock_init(&queue->irqlock); | |
86 | INIT_LIST_HEAD(&queue->mainqueue); | |
87 | INIT_LIST_HEAD(&queue->irqqueue); | |
9bde9f26 | 88 | queue->flags = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0; |
ff924203 | 89 | queue->type = type; |
c0efd232 LP |
90 | } |
91 | ||
8e815e17 LP |
92 | /* |
93 | * Free the video buffers. | |
94 | * | |
95 | * This function must be called with the queue lock held. | |
96 | */ | |
97 | static int __uvc_free_buffers(struct uvc_video_queue *queue) | |
98 | { | |
99 | unsigned int i; | |
100 | ||
101 | for (i = 0; i < queue->count; ++i) { | |
102 | if (queue->buffer[i].vma_use_count != 0) | |
103 | return -EBUSY; | |
104 | } | |
105 | ||
106 | if (queue->count) { | |
107 | vfree(queue->mem); | |
108 | queue->count = 0; | |
109 | } | |
110 | ||
111 | return 0; | |
112 | } | |
113 | ||
114 | int uvc_free_buffers(struct uvc_video_queue *queue) | |
115 | { | |
116 | int ret; | |
117 | ||
118 | mutex_lock(&queue->mutex); | |
119 | ret = __uvc_free_buffers(queue); | |
120 | mutex_unlock(&queue->mutex); | |
121 | ||
122 | return ret; | |
123 | } | |
124 | ||
c0efd232 LP |
125 | /* |
126 | * Allocate the video buffers. | |
127 | * | |
2c2d264b LP |
128 | * Pages are reserved to make sure they will not be swapped, as they will be |
129 | * filled in the URB completion handler. | |
c0efd232 LP |
130 | * |
131 | * Buffers will be individually mapped, so they must all be page aligned. | |
132 | */ | |
133 | int uvc_alloc_buffers(struct uvc_video_queue *queue, unsigned int nbuffers, | |
134 | unsigned int buflength) | |
135 | { | |
136 | unsigned int bufsize = PAGE_ALIGN(buflength); | |
137 | unsigned int i; | |
138 | void *mem = NULL; | |
139 | int ret; | |
140 | ||
141 | if (nbuffers > UVC_MAX_VIDEO_BUFFERS) | |
142 | nbuffers = UVC_MAX_VIDEO_BUFFERS; | |
143 | ||
144 | mutex_lock(&queue->mutex); | |
145 | ||
8e815e17 | 146 | if ((ret = __uvc_free_buffers(queue)) < 0) |
c0efd232 LP |
147 | goto done; |
148 | ||
149 | /* Bail out if no buffers should be allocated. */ | |
150 | if (nbuffers == 0) | |
151 | goto done; | |
152 | ||
153 | /* Decrement the number of buffers until allocation succeeds. */ | |
154 | for (; nbuffers > 0; --nbuffers) { | |
155 | mem = vmalloc_32(nbuffers * bufsize); | |
156 | if (mem != NULL) | |
157 | break; | |
158 | } | |
159 | ||
160 | if (mem == NULL) { | |
161 | ret = -ENOMEM; | |
162 | goto done; | |
163 | } | |
164 | ||
165 | for (i = 0; i < nbuffers; ++i) { | |
166 | memset(&queue->buffer[i], 0, sizeof queue->buffer[i]); | |
167 | queue->buffer[i].buf.index = i; | |
168 | queue->buffer[i].buf.m.offset = i * bufsize; | |
169 | queue->buffer[i].buf.length = buflength; | |
ff924203 | 170 | queue->buffer[i].buf.type = queue->type; |
c0efd232 LP |
171 | queue->buffer[i].buf.field = V4L2_FIELD_NONE; |
172 | queue->buffer[i].buf.memory = V4L2_MEMORY_MMAP; | |
173 | queue->buffer[i].buf.flags = 0; | |
174 | init_waitqueue_head(&queue->buffer[i].wait); | |
175 | } | |
176 | ||
177 | queue->mem = mem; | |
178 | queue->count = nbuffers; | |
179 | queue->buf_size = bufsize; | |
180 | ret = nbuffers; | |
181 | ||
182 | done: | |
183 | mutex_unlock(&queue->mutex); | |
184 | return ret; | |
185 | } | |
186 | ||
23ff6043 LP |
187 | /* |
188 | * Check if buffers have been allocated. | |
189 | */ | |
190 | int uvc_queue_allocated(struct uvc_video_queue *queue) | |
191 | { | |
192 | int allocated; | |
193 | ||
194 | mutex_lock(&queue->mutex); | |
195 | allocated = queue->count != 0; | |
196 | mutex_unlock(&queue->mutex); | |
197 | ||
198 | return allocated; | |
199 | } | |
200 | ||
c0efd232 LP |
201 | static void __uvc_query_buffer(struct uvc_buffer *buf, |
202 | struct v4l2_buffer *v4l2_buf) | |
203 | { | |
204 | memcpy(v4l2_buf, &buf->buf, sizeof *v4l2_buf); | |
205 | ||
206 | if (buf->vma_use_count) | |
207 | v4l2_buf->flags |= V4L2_BUF_FLAG_MAPPED; | |
208 | ||
209 | switch (buf->state) { | |
210 | case UVC_BUF_STATE_ERROR: | |
211 | case UVC_BUF_STATE_DONE: | |
212 | v4l2_buf->flags |= V4L2_BUF_FLAG_DONE; | |
213 | break; | |
214 | case UVC_BUF_STATE_QUEUED: | |
215 | case UVC_BUF_STATE_ACTIVE: | |
d7c0d439 | 216 | case UVC_BUF_STATE_READY: |
c0efd232 LP |
217 | v4l2_buf->flags |= V4L2_BUF_FLAG_QUEUED; |
218 | break; | |
219 | case UVC_BUF_STATE_IDLE: | |
220 | default: | |
221 | break; | |
222 | } | |
223 | } | |
224 | ||
225 | int uvc_query_buffer(struct uvc_video_queue *queue, | |
226 | struct v4l2_buffer *v4l2_buf) | |
227 | { | |
228 | int ret = 0; | |
229 | ||
230 | mutex_lock(&queue->mutex); | |
231 | if (v4l2_buf->index >= queue->count) { | |
232 | ret = -EINVAL; | |
233 | goto done; | |
234 | } | |
235 | ||
236 | __uvc_query_buffer(&queue->buffer[v4l2_buf->index], v4l2_buf); | |
237 | ||
238 | done: | |
2c2d264b LP |
239 | mutex_unlock(&queue->mutex); |
240 | return ret; | |
c0efd232 LP |
241 | } |
242 | ||
243 | /* | |
244 | * Queue a video buffer. Attempting to queue a buffer that has already been | |
245 | * queued will return -EINVAL. | |
246 | */ | |
247 | int uvc_queue_buffer(struct uvc_video_queue *queue, | |
248 | struct v4l2_buffer *v4l2_buf) | |
249 | { | |
250 | struct uvc_buffer *buf; | |
251 | unsigned long flags; | |
252 | int ret = 0; | |
253 | ||
254 | uvc_trace(UVC_TRACE_CAPTURE, "Queuing buffer %u.\n", v4l2_buf->index); | |
255 | ||
ff924203 | 256 | if (v4l2_buf->type != queue->type || |
c0efd232 LP |
257 | v4l2_buf->memory != V4L2_MEMORY_MMAP) { |
258 | uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer type (%u) " | |
259 | "and/or memory (%u).\n", v4l2_buf->type, | |
260 | v4l2_buf->memory); | |
261 | return -EINVAL; | |
262 | } | |
263 | ||
264 | mutex_lock(&queue->mutex); | |
2c2d264b | 265 | if (v4l2_buf->index >= queue->count) { |
c0efd232 LP |
266 | uvc_trace(UVC_TRACE_CAPTURE, "[E] Out of range index.\n"); |
267 | ret = -EINVAL; | |
268 | goto done; | |
269 | } | |
270 | ||
271 | buf = &queue->buffer[v4l2_buf->index]; | |
272 | if (buf->state != UVC_BUF_STATE_IDLE) { | |
273 | uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer state " | |
274 | "(%u).\n", buf->state); | |
275 | ret = -EINVAL; | |
276 | goto done; | |
277 | } | |
278 | ||
ff924203 LP |
279 | if (v4l2_buf->type == V4L2_BUF_TYPE_VIDEO_OUTPUT && |
280 | v4l2_buf->bytesused > buf->buf.length) { | |
281 | uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n"); | |
282 | ret = -EINVAL; | |
283 | goto done; | |
284 | } | |
285 | ||
c0efd232 LP |
286 | spin_lock_irqsave(&queue->irqlock, flags); |
287 | if (queue->flags & UVC_QUEUE_DISCONNECTED) { | |
288 | spin_unlock_irqrestore(&queue->irqlock, flags); | |
289 | ret = -ENODEV; | |
290 | goto done; | |
291 | } | |
292 | buf->state = UVC_BUF_STATE_QUEUED; | |
ff924203 LP |
293 | if (v4l2_buf->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) |
294 | buf->buf.bytesused = 0; | |
295 | else | |
296 | buf->buf.bytesused = v4l2_buf->bytesused; | |
297 | ||
c0efd232 LP |
298 | list_add_tail(&buf->stream, &queue->mainqueue); |
299 | list_add_tail(&buf->queue, &queue->irqqueue); | |
300 | spin_unlock_irqrestore(&queue->irqlock, flags); | |
301 | ||
302 | done: | |
303 | mutex_unlock(&queue->mutex); | |
304 | return ret; | |
305 | } | |
306 | ||
307 | static int uvc_queue_waiton(struct uvc_buffer *buf, int nonblocking) | |
308 | { | |
309 | if (nonblocking) { | |
310 | return (buf->state != UVC_BUF_STATE_QUEUED && | |
d7c0d439 LP |
311 | buf->state != UVC_BUF_STATE_ACTIVE && |
312 | buf->state != UVC_BUF_STATE_READY) | |
c0efd232 LP |
313 | ? 0 : -EAGAIN; |
314 | } | |
315 | ||
316 | return wait_event_interruptible(buf->wait, | |
317 | buf->state != UVC_BUF_STATE_QUEUED && | |
d7c0d439 LP |
318 | buf->state != UVC_BUF_STATE_ACTIVE && |
319 | buf->state != UVC_BUF_STATE_READY); | |
c0efd232 LP |
320 | } |
321 | ||
322 | /* | |
323 | * Dequeue a video buffer. If nonblocking is false, block until a buffer is | |
324 | * available. | |
325 | */ | |
326 | int uvc_dequeue_buffer(struct uvc_video_queue *queue, | |
327 | struct v4l2_buffer *v4l2_buf, int nonblocking) | |
328 | { | |
329 | struct uvc_buffer *buf; | |
330 | int ret = 0; | |
331 | ||
ff924203 | 332 | if (v4l2_buf->type != queue->type || |
c0efd232 LP |
333 | v4l2_buf->memory != V4L2_MEMORY_MMAP) { |
334 | uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer type (%u) " | |
335 | "and/or memory (%u).\n", v4l2_buf->type, | |
336 | v4l2_buf->memory); | |
337 | return -EINVAL; | |
338 | } | |
339 | ||
340 | mutex_lock(&queue->mutex); | |
341 | if (list_empty(&queue->mainqueue)) { | |
342 | uvc_trace(UVC_TRACE_CAPTURE, "[E] Empty buffer queue.\n"); | |
343 | ret = -EINVAL; | |
344 | goto done; | |
345 | } | |
346 | ||
347 | buf = list_first_entry(&queue->mainqueue, struct uvc_buffer, stream); | |
348 | if ((ret = uvc_queue_waiton(buf, nonblocking)) < 0) | |
349 | goto done; | |
350 | ||
351 | uvc_trace(UVC_TRACE_CAPTURE, "Dequeuing buffer %u (%u, %u bytes).\n", | |
352 | buf->buf.index, buf->state, buf->buf.bytesused); | |
353 | ||
354 | switch (buf->state) { | |
355 | case UVC_BUF_STATE_ERROR: | |
356 | uvc_trace(UVC_TRACE_CAPTURE, "[W] Corrupted data " | |
357 | "(transmission error).\n"); | |
358 | ret = -EIO; | |
359 | case UVC_BUF_STATE_DONE: | |
360 | buf->state = UVC_BUF_STATE_IDLE; | |
361 | break; | |
362 | ||
363 | case UVC_BUF_STATE_IDLE: | |
364 | case UVC_BUF_STATE_QUEUED: | |
365 | case UVC_BUF_STATE_ACTIVE: | |
d7c0d439 | 366 | case UVC_BUF_STATE_READY: |
c0efd232 LP |
367 | default: |
368 | uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer state %u " | |
369 | "(driver bug?).\n", buf->state); | |
370 | ret = -EINVAL; | |
371 | goto done; | |
372 | } | |
373 | ||
374 | list_del(&buf->stream); | |
375 | __uvc_query_buffer(buf, v4l2_buf); | |
376 | ||
377 | done: | |
378 | mutex_unlock(&queue->mutex); | |
379 | return ret; | |
380 | } | |
381 | ||
4aa27597 LP |
382 | /* |
383 | * VMA operations. | |
384 | */ | |
385 | static void uvc_vm_open(struct vm_area_struct *vma) | |
386 | { | |
387 | struct uvc_buffer *buffer = vma->vm_private_data; | |
388 | buffer->vma_use_count++; | |
389 | } | |
390 | ||
391 | static void uvc_vm_close(struct vm_area_struct *vma) | |
392 | { | |
393 | struct uvc_buffer *buffer = vma->vm_private_data; | |
394 | buffer->vma_use_count--; | |
395 | } | |
396 | ||
397 | static const struct vm_operations_struct uvc_vm_ops = { | |
398 | .open = uvc_vm_open, | |
399 | .close = uvc_vm_close, | |
400 | }; | |
401 | ||
402 | /* | |
403 | * Memory-map a video buffer. | |
404 | * | |
405 | * This function implements video buffers memory mapping and is intended to be | |
406 | * used by the device mmap handler. | |
407 | */ | |
408 | int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma) | |
409 | { | |
410 | struct uvc_buffer *uninitialized_var(buffer); | |
411 | struct page *page; | |
412 | unsigned long addr, start, size; | |
413 | unsigned int i; | |
414 | int ret = 0; | |
415 | ||
416 | start = vma->vm_start; | |
417 | size = vma->vm_end - vma->vm_start; | |
418 | ||
419 | mutex_lock(&queue->mutex); | |
420 | ||
421 | for (i = 0; i < queue->count; ++i) { | |
422 | buffer = &queue->buffer[i]; | |
423 | if ((buffer->buf.m.offset >> PAGE_SHIFT) == vma->vm_pgoff) | |
424 | break; | |
425 | } | |
426 | ||
72969447 | 427 | if (i == queue->count || PAGE_ALIGN(size) != queue->buf_size) { |
4aa27597 LP |
428 | ret = -EINVAL; |
429 | goto done; | |
430 | } | |
431 | ||
432 | /* | |
433 | * VM_IO marks the area as being an mmaped region for I/O to a | |
434 | * device. It also prevents the region from being core dumped. | |
435 | */ | |
436 | vma->vm_flags |= VM_IO; | |
437 | ||
438 | addr = (unsigned long)queue->mem + buffer->buf.m.offset; | |
72969447 | 439 | #ifdef CONFIG_MMU |
4aa27597 LP |
440 | while (size > 0) { |
441 | page = vmalloc_to_page((void *)addr); | |
442 | if ((ret = vm_insert_page(vma, start, page)) < 0) | |
443 | goto done; | |
444 | ||
445 | start += PAGE_SIZE; | |
446 | addr += PAGE_SIZE; | |
447 | size -= PAGE_SIZE; | |
448 | } | |
72969447 | 449 | #endif |
4aa27597 LP |
450 | |
451 | vma->vm_ops = &uvc_vm_ops; | |
452 | vma->vm_private_data = buffer; | |
453 | uvc_vm_open(vma); | |
454 | ||
455 | done: | |
456 | mutex_unlock(&queue->mutex); | |
457 | return ret; | |
458 | } | |
459 | ||
c0efd232 LP |
460 | /* |
461 | * Poll the video queue. | |
462 | * | |
463 | * This function implements video queue polling and is intended to be used by | |
464 | * the device poll handler. | |
465 | */ | |
466 | unsigned int uvc_queue_poll(struct uvc_video_queue *queue, struct file *file, | |
467 | poll_table *wait) | |
468 | { | |
469 | struct uvc_buffer *buf; | |
470 | unsigned int mask = 0; | |
471 | ||
472 | mutex_lock(&queue->mutex); | |
473 | if (list_empty(&queue->mainqueue)) { | |
474 | mask |= POLLERR; | |
475 | goto done; | |
476 | } | |
477 | buf = list_first_entry(&queue->mainqueue, struct uvc_buffer, stream); | |
478 | ||
479 | poll_wait(file, &buf->wait, wait); | |
480 | if (buf->state == UVC_BUF_STATE_DONE || | |
ed3de601 LP |
481 | buf->state == UVC_BUF_STATE_ERROR) { |
482 | if (queue->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) | |
483 | mask |= POLLIN | POLLRDNORM; | |
484 | else | |
485 | mask |= POLLOUT | POLLWRNORM; | |
486 | } | |
c0efd232 LP |
487 | |
488 | done: | |
489 | mutex_unlock(&queue->mutex); | |
490 | return mask; | |
491 | } | |
492 | ||
72969447 BL |
493 | #ifndef CONFIG_MMU |
494 | /* | |
495 | * Get unmapped area. | |
496 | * | |
497 | * NO-MMU arch need this function to make mmap() work correctly. | |
498 | */ | |
499 | unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue, | |
500 | unsigned long pgoff) | |
501 | { | |
502 | struct uvc_buffer *buffer; | |
503 | unsigned int i; | |
504 | unsigned long ret; | |
505 | ||
506 | mutex_lock(&queue->mutex); | |
507 | for (i = 0; i < queue->count; ++i) { | |
508 | buffer = &queue->buffer[i]; | |
509 | if ((buffer->buf.m.offset >> PAGE_SHIFT) == pgoff) | |
510 | break; | |
511 | } | |
512 | if (i == queue->count) { | |
513 | ret = -EINVAL; | |
514 | goto done; | |
515 | } | |
516 | ret = (unsigned long)queue->mem + buffer->buf.m.offset; | |
517 | done: | |
518 | mutex_unlock(&queue->mutex); | |
519 | return ret; | |
520 | } | |
521 | #endif | |
522 | ||
c0efd232 LP |
523 | /* |
524 | * Enable or disable the video buffers queue. | |
525 | * | |
526 | * The queue must be enabled before starting video acquisition and must be | |
527 | * disabled after stopping it. This ensures that the video buffers queue | |
528 | * state can be properly initialized before buffers are accessed from the | |
529 | * interrupt handler. | |
530 | * | |
650b95fe | 531 | * Enabling the video queue returns -EBUSY if the queue is already enabled. |
c0efd232 LP |
532 | * |
533 | * Disabling the video queue cancels the queue and removes all buffers from | |
534 | * the main queue. | |
535 | * | |
536 | * This function can't be called from interrupt context. Use | |
537 | * uvc_queue_cancel() instead. | |
538 | */ | |
539 | int uvc_queue_enable(struct uvc_video_queue *queue, int enable) | |
540 | { | |
541 | unsigned int i; | |
542 | int ret = 0; | |
543 | ||
544 | mutex_lock(&queue->mutex); | |
545 | if (enable) { | |
546 | if (uvc_queue_streaming(queue)) { | |
547 | ret = -EBUSY; | |
548 | goto done; | |
549 | } | |
c0efd232 | 550 | queue->flags |= UVC_QUEUE_STREAMING; |
ff924203 | 551 | queue->buf_used = 0; |
c0efd232 LP |
552 | } else { |
553 | uvc_queue_cancel(queue, 0); | |
554 | INIT_LIST_HEAD(&queue->mainqueue); | |
555 | ||
9bde9f26 LP |
556 | for (i = 0; i < queue->count; ++i) { |
557 | queue->buffer[i].error = 0; | |
c0efd232 | 558 | queue->buffer[i].state = UVC_BUF_STATE_IDLE; |
9bde9f26 | 559 | } |
c0efd232 LP |
560 | |
561 | queue->flags &= ~UVC_QUEUE_STREAMING; | |
562 | } | |
563 | ||
564 | done: | |
565 | mutex_unlock(&queue->mutex); | |
566 | return ret; | |
567 | } | |
568 | ||
569 | /* | |
570 | * Cancel the video buffers queue. | |
571 | * | |
572 | * Cancelling the queue marks all buffers on the irq queue as erroneous, | |
2c2d264b | 573 | * wakes them up and removes them from the queue. |
c0efd232 LP |
574 | * |
575 | * If the disconnect parameter is set, further calls to uvc_queue_buffer will | |
576 | * fail with -ENODEV. | |
577 | * | |
578 | * This function acquires the irq spinlock and can be called from interrupt | |
579 | * context. | |
580 | */ | |
581 | void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect) | |
582 | { | |
583 | struct uvc_buffer *buf; | |
584 | unsigned long flags; | |
585 | ||
586 | spin_lock_irqsave(&queue->irqlock, flags); | |
587 | while (!list_empty(&queue->irqqueue)) { | |
588 | buf = list_first_entry(&queue->irqqueue, struct uvc_buffer, | |
589 | queue); | |
590 | list_del(&buf->queue); | |
591 | buf->state = UVC_BUF_STATE_ERROR; | |
592 | wake_up(&buf->wait); | |
593 | } | |
594 | /* This must be protected by the irqlock spinlock to avoid race | |
595 | * conditions between uvc_queue_buffer and the disconnection event that | |
596 | * could result in an interruptible wait in uvc_dequeue_buffer. Do not | |
597 | * blindly replace this logic by checking for the UVC_DEV_DISCONNECTED | |
598 | * state outside the queue code. | |
599 | */ | |
600 | if (disconnect) | |
601 | queue->flags |= UVC_QUEUE_DISCONNECTED; | |
602 | spin_unlock_irqrestore(&queue->irqlock, flags); | |
603 | } | |
604 | ||
605 | struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue, | |
606 | struct uvc_buffer *buf) | |
607 | { | |
608 | struct uvc_buffer *nextbuf; | |
609 | unsigned long flags; | |
610 | ||
9bde9f26 LP |
611 | if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) { |
612 | buf->error = 0; | |
c0efd232 LP |
613 | buf->state = UVC_BUF_STATE_QUEUED; |
614 | buf->buf.bytesused = 0; | |
615 | return buf; | |
616 | } | |
617 | ||
618 | spin_lock_irqsave(&queue->irqlock, flags); | |
619 | list_del(&buf->queue); | |
9bde9f26 | 620 | buf->error = 0; |
d7c0d439 | 621 | buf->state = UVC_BUF_STATE_DONE; |
c0efd232 LP |
622 | if (!list_empty(&queue->irqqueue)) |
623 | nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer, | |
624 | queue); | |
625 | else | |
626 | nextbuf = NULL; | |
627 | spin_unlock_irqrestore(&queue->irqlock, flags); | |
628 | ||
c0efd232 LP |
629 | wake_up(&buf->wait); |
630 | return nextbuf; | |
631 | } | |
f87086e3 | 632 |