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1/*
2 * uvc_queue.c -- USB Video Class driver - Buffers management
3 *
4 * Copyright (C) 2005-2010
5 * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
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#include <linux/atomic.h>
14#include <linux/kernel.h>
15#include <linux/mm.h>
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
23#include <media/v4l2-common.h>
24#include <media/videobuf2-vmalloc.h>
25
26#include "uvc.h"
27
28/* ------------------------------------------------------------------------
29 * Video buffers queue management.
30 *
31 * Video queues is initialized by uvcg_queue_init(). The function performs
32 * basic initialization of the uvc_video_queue struct and never fails.
33 *
34 * Video buffers are managed by videobuf2. The driver uses a mutex to protect
35 * the videobuf2 queue operations by serializing calls to videobuf2 and a
36 * spinlock to protect the IRQ queue that holds the buffers to be processed by
37 * the driver.
38 */
39
40/* -----------------------------------------------------------------------------
41 * videobuf2 queue operations
42 */
43
44static int uvc_queue_setup(struct vb2_queue *vq,
45 unsigned int *nbuffers, unsigned int *nplanes,
46 unsigned int sizes[], struct device *alloc_devs[])
47{
48 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
49 struct uvc_video *video = container_of(queue, struct uvc_video, queue);
50
51 if (*nbuffers > UVC_MAX_VIDEO_BUFFERS)
52 *nbuffers = UVC_MAX_VIDEO_BUFFERS;
53
54 *nplanes = 1;
55
56 sizes[0] = video->imagesize;
57
58 return 0;
59}
60
61static int uvc_buffer_prepare(struct vb2_buffer *vb)
62{
63 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
64 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
65 struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
66
67 if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
68 vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
69 uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
70 return -EINVAL;
71 }
72
73 if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
74 return -ENODEV;
75
76 buf->state = UVC_BUF_STATE_QUEUED;
77 buf->mem = vb2_plane_vaddr(vb, 0);
78 buf->length = vb2_plane_size(vb, 0);
79 if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
80 buf->bytesused = 0;
81 else
82 buf->bytesused = vb2_get_plane_payload(vb, 0);
83
84 return 0;
85}
86
87static void uvc_buffer_queue(struct vb2_buffer *vb)
88{
89 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
90 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
91 struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
92 unsigned long flags;
93
94 spin_lock_irqsave(&queue->irqlock, flags);
95
96 if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
97 list_add_tail(&buf->queue, &queue->irqqueue);
98 } else {
99 /* If the device is disconnected return the buffer to userspace
100 * directly. The next QBUF call will fail with -ENODEV.
101 */
102 buf->state = UVC_BUF_STATE_ERROR;
103 vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
104 }
105
106 spin_unlock_irqrestore(&queue->irqlock, flags);
107}
108
109static struct vb2_ops uvc_queue_qops = {
110 .queue_setup = uvc_queue_setup,
111 .buf_prepare = uvc_buffer_prepare,
112 .buf_queue = uvc_buffer_queue,
113 .wait_prepare = vb2_ops_wait_prepare,
114 .wait_finish = vb2_ops_wait_finish,
115};
116
117int uvcg_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
118 struct mutex *lock)
119{
120 int ret;
121
122 queue->queue.type = type;
123 queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
124 queue->queue.drv_priv = queue;
125 queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
126 queue->queue.ops = &uvc_queue_qops;
127 queue->queue.lock = lock;
128 queue->queue.mem_ops = &vb2_vmalloc_memops;
129 queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
130 | V4L2_BUF_FLAG_TSTAMP_SRC_EOF;
131 ret = vb2_queue_init(&queue->queue);
132 if (ret)
133 return ret;
134
135 spin_lock_init(&queue->irqlock);
136 INIT_LIST_HEAD(&queue->irqqueue);
137 queue->flags = 0;
138
139 return 0;
140}
141
142/*
143 * Free the video buffers.
144 */
145void uvcg_free_buffers(struct uvc_video_queue *queue)
146{
147 vb2_queue_release(&queue->queue);
148}
149
150/*
151 * Allocate the video buffers.
152 */
153int uvcg_alloc_buffers(struct uvc_video_queue *queue,
154 struct v4l2_requestbuffers *rb)
155{
156 int ret;
157
158 ret = vb2_reqbufs(&queue->queue, rb);
159
160 return ret ? ret : rb->count;
161}
162
163int uvcg_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
164{
165 return vb2_querybuf(&queue->queue, buf);
166}
167
168int uvcg_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
169{
170 unsigned long flags;
171 int ret;
172
173 ret = vb2_qbuf(&queue->queue, buf);
174 if (ret < 0)
175 return ret;
176
177 spin_lock_irqsave(&queue->irqlock, flags);
178 ret = (queue->flags & UVC_QUEUE_PAUSED) != 0;
179 queue->flags &= ~UVC_QUEUE_PAUSED;
180 spin_unlock_irqrestore(&queue->irqlock, flags);
181 return ret;
182}
183
184/*
185 * Dequeue a video buffer. If nonblocking is false, block until a buffer is
186 * available.
187 */
188int uvcg_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
189 int nonblocking)
190{
191 return vb2_dqbuf(&queue->queue, buf, nonblocking);
192}
193
194/*
195 * Poll the video queue.
196 *
197 * This function implements video queue polling and is intended to be used by
198 * the device poll handler.
199 */
200unsigned int uvcg_queue_poll(struct uvc_video_queue *queue, struct file *file,
201 poll_table *wait)
202{
203 return vb2_poll(&queue->queue, file, wait);
204}
205
206int uvcg_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
207{
208 return vb2_mmap(&queue->queue, vma);
209}
210
211#ifndef CONFIG_MMU
212/*
213 * Get unmapped area.
214 *
215 * NO-MMU arch need this function to make mmap() work correctly.
216 */
217unsigned long uvcg_queue_get_unmapped_area(struct uvc_video_queue *queue,
218 unsigned long pgoff)
219{
220 return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
221}
222#endif
223
224/*
225 * Cancel the video buffers queue.
226 *
227 * Cancelling the queue marks all buffers on the irq queue as erroneous,
228 * wakes them up and removes them from the queue.
229 *
230 * If the disconnect parameter is set, further calls to uvc_queue_buffer will
231 * fail with -ENODEV.
232 *
233 * This function acquires the irq spinlock and can be called from interrupt
234 * context.
235 */
236void uvcg_queue_cancel(struct uvc_video_queue *queue, int disconnect)
237{
238 struct uvc_buffer *buf;
239 unsigned long flags;
240
241 spin_lock_irqsave(&queue->irqlock, flags);
242 while (!list_empty(&queue->irqqueue)) {
243 buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
244 queue);
245 list_del(&buf->queue);
246 buf->state = UVC_BUF_STATE_ERROR;
247 vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_ERROR);
248 }
249 /* This must be protected by the irqlock spinlock to avoid race
250 * conditions between uvc_queue_buffer and the disconnection event that
251 * could result in an interruptible wait in uvc_dequeue_buffer. Do not
252 * blindly replace this logic by checking for the UVC_DEV_DISCONNECTED
253 * state outside the queue code.
254 */
255 if (disconnect)
256 queue->flags |= UVC_QUEUE_DISCONNECTED;
257 spin_unlock_irqrestore(&queue->irqlock, flags);
258}
259
260/*
261 * Enable or disable the video buffers queue.
262 *
263 * The queue must be enabled before starting video acquisition and must be
264 * disabled after stopping it. This ensures that the video buffers queue
265 * state can be properly initialized before buffers are accessed from the
266 * interrupt handler.
267 *
268 * Enabling the video queue initializes parameters (such as sequence number,
269 * sync pattern, ...). If the queue is already enabled, return -EBUSY.
270 *
271 * Disabling the video queue cancels the queue and removes all buffers from
272 * the main queue.
273 *
274 * This function can't be called from interrupt context. Use
275 * uvcg_queue_cancel() instead.
276 */
277int uvcg_queue_enable(struct uvc_video_queue *queue, int enable)
278{
279 unsigned long flags;
280 int ret = 0;
281
282 if (enable) {
283 ret = vb2_streamon(&queue->queue, queue->queue.type);
284 if (ret < 0)
285 return ret;
286
287 queue->sequence = 0;
288 queue->buf_used = 0;
289 } else {
290 ret = vb2_streamoff(&queue->queue, queue->queue.type);
291 if (ret < 0)
292 return ret;
293
294 spin_lock_irqsave(&queue->irqlock, flags);
295 INIT_LIST_HEAD(&queue->irqqueue);
296
297 /*
298 * FIXME: We need to clear the DISCONNECTED flag to ensure that
299 * applications will be able to queue buffers for the next
300 * streaming run. However, clearing it here doesn't guarantee
301 * that the device will be reconnected in the meantime.
302 */
303 queue->flags &= ~UVC_QUEUE_DISCONNECTED;
304 spin_unlock_irqrestore(&queue->irqlock, flags);
305 }
306
307 return ret;
308}
309
310/* called with &queue_irqlock held.. */
311struct uvc_buffer *uvcg_queue_next_buffer(struct uvc_video_queue *queue,
312 struct uvc_buffer *buf)
313{
314 struct uvc_buffer *nextbuf;
315
316 if ((queue->flags & UVC_QUEUE_DROP_INCOMPLETE) &&
317 buf->length != buf->bytesused) {
318 buf->state = UVC_BUF_STATE_QUEUED;
319 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
320 return buf;
321 }
322
323 list_del(&buf->queue);
324 if (!list_empty(&queue->irqqueue))
325 nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
326 queue);
327 else
328 nextbuf = NULL;
329
330 buf->buf.field = V4L2_FIELD_NONE;
331 buf->buf.sequence = queue->sequence++;
332 buf->buf.vb2_buf.timestamp = ktime_get_ns();
333
334 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
335 vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
336
337 return nextbuf;
338}
339
340struct uvc_buffer *uvcg_queue_head(struct uvc_video_queue *queue)
341{
342 struct uvc_buffer *buf = NULL;
343
344 if (!list_empty(&queue->irqqueue))
345 buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
346 queue);
347 else
348 queue->flags |= UVC_QUEUE_PAUSED;
349
350 return buf;
351}
352
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * uvc_queue.c -- USB Video Class driver - Buffers management
4 *
5 * Copyright (C) 2005-2010
6 * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
7 */
8
9#include <linux/atomic.h>
10#include <linux/kernel.h>
11#include <linux/mm.h>
12#include <linux/list.h>
13#include <linux/module.h>
14#include <linux/usb.h>
15#include <linux/videodev2.h>
16#include <linux/vmalloc.h>
17#include <linux/wait.h>
18
19#include <media/v4l2-common.h>
20#include <media/videobuf2-vmalloc.h>
21
22#include "uvc.h"
23
24/* ------------------------------------------------------------------------
25 * Video buffers queue management.
26 *
27 * Video queues is initialized by uvcg_queue_init(). The function performs
28 * basic initialization of the uvc_video_queue struct and never fails.
29 *
30 * Video buffers are managed by videobuf2. The driver uses a mutex to protect
31 * the videobuf2 queue operations by serializing calls to videobuf2 and a
32 * spinlock to protect the IRQ queue that holds the buffers to be processed by
33 * the driver.
34 */
35
36/* -----------------------------------------------------------------------------
37 * videobuf2 queue operations
38 */
39
40static int uvc_queue_setup(struct vb2_queue *vq,
41 unsigned int *nbuffers, unsigned int *nplanes,
42 unsigned int sizes[], struct device *alloc_devs[])
43{
44 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
45 struct uvc_video *video = container_of(queue, struct uvc_video, queue);
46
47 if (*nbuffers > UVC_MAX_VIDEO_BUFFERS)
48 *nbuffers = UVC_MAX_VIDEO_BUFFERS;
49
50 *nplanes = 1;
51
52 sizes[0] = video->imagesize;
53
54 return 0;
55}
56
57static int uvc_buffer_prepare(struct vb2_buffer *vb)
58{
59 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
60 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
61 struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
62
63 if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
64 vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
65 uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
66 return -EINVAL;
67 }
68
69 if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
70 return -ENODEV;
71
72 buf->state = UVC_BUF_STATE_QUEUED;
73 buf->mem = vb2_plane_vaddr(vb, 0);
74 buf->length = vb2_plane_size(vb, 0);
75 if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
76 buf->bytesused = 0;
77 else
78 buf->bytesused = vb2_get_plane_payload(vb, 0);
79
80 return 0;
81}
82
83static void uvc_buffer_queue(struct vb2_buffer *vb)
84{
85 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
86 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
87 struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
88 unsigned long flags;
89
90 spin_lock_irqsave(&queue->irqlock, flags);
91
92 if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
93 list_add_tail(&buf->queue, &queue->irqqueue);
94 } else {
95 /* If the device is disconnected return the buffer to userspace
96 * directly. The next QBUF call will fail with -ENODEV.
97 */
98 buf->state = UVC_BUF_STATE_ERROR;
99 vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
100 }
101
102 spin_unlock_irqrestore(&queue->irqlock, flags);
103}
104
105static const struct vb2_ops uvc_queue_qops = {
106 .queue_setup = uvc_queue_setup,
107 .buf_prepare = uvc_buffer_prepare,
108 .buf_queue = uvc_buffer_queue,
109 .wait_prepare = vb2_ops_wait_prepare,
110 .wait_finish = vb2_ops_wait_finish,
111};
112
113int uvcg_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
114 struct mutex *lock)
115{
116 int ret;
117
118 queue->queue.type = type;
119 queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
120 queue->queue.drv_priv = queue;
121 queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
122 queue->queue.ops = &uvc_queue_qops;
123 queue->queue.lock = lock;
124 queue->queue.mem_ops = &vb2_vmalloc_memops;
125 queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
126 | V4L2_BUF_FLAG_TSTAMP_SRC_EOF;
127 ret = vb2_queue_init(&queue->queue);
128 if (ret)
129 return ret;
130
131 spin_lock_init(&queue->irqlock);
132 INIT_LIST_HEAD(&queue->irqqueue);
133 queue->flags = 0;
134
135 return 0;
136}
137
138/*
139 * Free the video buffers.
140 */
141void uvcg_free_buffers(struct uvc_video_queue *queue)
142{
143 vb2_queue_release(&queue->queue);
144}
145
146/*
147 * Allocate the video buffers.
148 */
149int uvcg_alloc_buffers(struct uvc_video_queue *queue,
150 struct v4l2_requestbuffers *rb)
151{
152 int ret;
153
154 ret = vb2_reqbufs(&queue->queue, rb);
155
156 return ret ? ret : rb->count;
157}
158
159int uvcg_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
160{
161 return vb2_querybuf(&queue->queue, buf);
162}
163
164int uvcg_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
165{
166 unsigned long flags;
167 int ret;
168
169 ret = vb2_qbuf(&queue->queue, NULL, buf);
170 if (ret < 0)
171 return ret;
172
173 spin_lock_irqsave(&queue->irqlock, flags);
174 ret = (queue->flags & UVC_QUEUE_PAUSED) != 0;
175 queue->flags &= ~UVC_QUEUE_PAUSED;
176 spin_unlock_irqrestore(&queue->irqlock, flags);
177 return ret;
178}
179
180/*
181 * Dequeue a video buffer. If nonblocking is false, block until a buffer is
182 * available.
183 */
184int uvcg_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
185 int nonblocking)
186{
187 return vb2_dqbuf(&queue->queue, buf, nonblocking);
188}
189
190/*
191 * Poll the video queue.
192 *
193 * This function implements video queue polling and is intended to be used by
194 * the device poll handler.
195 */
196__poll_t uvcg_queue_poll(struct uvc_video_queue *queue, struct file *file,
197 poll_table *wait)
198{
199 return vb2_poll(&queue->queue, file, wait);
200}
201
202int uvcg_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
203{
204 return vb2_mmap(&queue->queue, vma);
205}
206
207#ifndef CONFIG_MMU
208/*
209 * Get unmapped area.
210 *
211 * NO-MMU arch need this function to make mmap() work correctly.
212 */
213unsigned long uvcg_queue_get_unmapped_area(struct uvc_video_queue *queue,
214 unsigned long pgoff)
215{
216 return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
217}
218#endif
219
220/*
221 * Cancel the video buffers queue.
222 *
223 * Cancelling the queue marks all buffers on the irq queue as erroneous,
224 * wakes them up and removes them from the queue.
225 *
226 * If the disconnect parameter is set, further calls to uvc_queue_buffer will
227 * fail with -ENODEV.
228 *
229 * This function acquires the irq spinlock and can be called from interrupt
230 * context.
231 */
232void uvcg_queue_cancel(struct uvc_video_queue *queue, int disconnect)
233{
234 struct uvc_buffer *buf;
235 unsigned long flags;
236
237 spin_lock_irqsave(&queue->irqlock, flags);
238 while (!list_empty(&queue->irqqueue)) {
239 buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
240 queue);
241 list_del(&buf->queue);
242 buf->state = UVC_BUF_STATE_ERROR;
243 vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_ERROR);
244 }
245 /* This must be protected by the irqlock spinlock to avoid race
246 * conditions between uvc_queue_buffer and the disconnection event that
247 * could result in an interruptible wait in uvc_dequeue_buffer. Do not
248 * blindly replace this logic by checking for the UVC_DEV_DISCONNECTED
249 * state outside the queue code.
250 */
251 if (disconnect)
252 queue->flags |= UVC_QUEUE_DISCONNECTED;
253 spin_unlock_irqrestore(&queue->irqlock, flags);
254}
255
256/*
257 * Enable or disable the video buffers queue.
258 *
259 * The queue must be enabled before starting video acquisition and must be
260 * disabled after stopping it. This ensures that the video buffers queue
261 * state can be properly initialized before buffers are accessed from the
262 * interrupt handler.
263 *
264 * Enabling the video queue initializes parameters (such as sequence number,
265 * sync pattern, ...). If the queue is already enabled, return -EBUSY.
266 *
267 * Disabling the video queue cancels the queue and removes all buffers from
268 * the main queue.
269 *
270 * This function can't be called from interrupt context. Use
271 * uvcg_queue_cancel() instead.
272 */
273int uvcg_queue_enable(struct uvc_video_queue *queue, int enable)
274{
275 unsigned long flags;
276 int ret = 0;
277
278 if (enable) {
279 ret = vb2_streamon(&queue->queue, queue->queue.type);
280 if (ret < 0)
281 return ret;
282
283 queue->sequence = 0;
284 queue->buf_used = 0;
285 } else {
286 ret = vb2_streamoff(&queue->queue, queue->queue.type);
287 if (ret < 0)
288 return ret;
289
290 spin_lock_irqsave(&queue->irqlock, flags);
291 INIT_LIST_HEAD(&queue->irqqueue);
292
293 /*
294 * FIXME: We need to clear the DISCONNECTED flag to ensure that
295 * applications will be able to queue buffers for the next
296 * streaming run. However, clearing it here doesn't guarantee
297 * that the device will be reconnected in the meantime.
298 */
299 queue->flags &= ~UVC_QUEUE_DISCONNECTED;
300 spin_unlock_irqrestore(&queue->irqlock, flags);
301 }
302
303 return ret;
304}
305
306/* called with &queue_irqlock held.. */
307struct uvc_buffer *uvcg_queue_next_buffer(struct uvc_video_queue *queue,
308 struct uvc_buffer *buf)
309{
310 struct uvc_buffer *nextbuf;
311
312 if ((queue->flags & UVC_QUEUE_DROP_INCOMPLETE) &&
313 buf->length != buf->bytesused) {
314 buf->state = UVC_BUF_STATE_QUEUED;
315 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
316 return buf;
317 }
318
319 list_del(&buf->queue);
320 if (!list_empty(&queue->irqqueue))
321 nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
322 queue);
323 else
324 nextbuf = NULL;
325
326 buf->buf.field = V4L2_FIELD_NONE;
327 buf->buf.sequence = queue->sequence++;
328 buf->buf.vb2_buf.timestamp = ktime_get_ns();
329
330 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
331 vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
332
333 return nextbuf;
334}
335
336struct uvc_buffer *uvcg_queue_head(struct uvc_video_queue *queue)
337{
338 struct uvc_buffer *buf = NULL;
339
340 if (!list_empty(&queue->irqqueue))
341 buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
342 queue);
343 else
344 queue->flags |= UVC_QUEUE_PAUSED;
345
346 return buf;
347}
348