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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-dma-sg.h>
21#include <media/videobuf2-vmalloc.h>
22
23#include "uvc.h"
24
25/* ------------------------------------------------------------------------
26 * Video buffers queue management.
27 *
28 * Video queues is initialized by uvcg_queue_init(). The function performs
29 * basic initialization of the uvc_video_queue struct and never fails.
30 *
31 * Video buffers are managed by videobuf2. The driver uses a mutex to protect
32 * the videobuf2 queue operations by serializing calls to videobuf2 and a
33 * spinlock to protect the IRQ queue that holds the buffers to be processed by
34 * the driver.
35 */
36
37/* -----------------------------------------------------------------------------
38 * videobuf2 queue operations
39 */
40
41static int uvc_queue_setup(struct vb2_queue *vq,
42 unsigned int *nbuffers, unsigned int *nplanes,
43 unsigned int sizes[], struct device *alloc_devs[])
44{
45 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
46 struct uvc_video *video = container_of(queue, struct uvc_video, queue);
47 unsigned int req_size;
48 unsigned int nreq;
49
50 if (*nbuffers > UVC_MAX_VIDEO_BUFFERS)
51 *nbuffers = UVC_MAX_VIDEO_BUFFERS;
52
53 *nplanes = 1;
54
55 sizes[0] = video->imagesize;
56
57 req_size = video->ep->maxpacket
58 * max_t(unsigned int, video->ep->maxburst, 1)
59 * (video->ep->mult);
60
61 /* We divide by two, to increase the chance to run
62 * into fewer requests for smaller framesizes.
63 */
64 nreq = DIV_ROUND_UP(DIV_ROUND_UP(sizes[0], 2), req_size);
65 nreq = clamp(nreq, 4U, 64U);
66 video->uvc_num_requests = nreq;
67
68 return 0;
69}
70
71static int uvc_buffer_prepare(struct vb2_buffer *vb)
72{
73 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
74 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
75 struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
76
77 if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
78 vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
79 uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
80 return -EINVAL;
81 }
82
83 if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
84 return -ENODEV;
85
86 buf->state = UVC_BUF_STATE_QUEUED;
87 if (queue->use_sg) {
88 buf->sgt = vb2_dma_sg_plane_desc(vb, 0);
89 buf->sg = buf->sgt->sgl;
90 } else {
91 buf->mem = vb2_plane_vaddr(vb, 0);
92 }
93 buf->length = vb2_plane_size(vb, 0);
94 if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
95 buf->bytesused = 0;
96 else
97 buf->bytesused = vb2_get_plane_payload(vb, 0);
98
99 return 0;
100}
101
102static void uvc_buffer_queue(struct vb2_buffer *vb)
103{
104 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
105 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
106 struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
107 unsigned long flags;
108
109 spin_lock_irqsave(&queue->irqlock, flags);
110
111 if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
112 list_add_tail(&buf->queue, &queue->irqqueue);
113 } else {
114 /*
115 * If the device is disconnected return the buffer to userspace
116 * directly. The next QBUF call will fail with -ENODEV.
117 */
118 buf->state = UVC_BUF_STATE_ERROR;
119 vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
120 }
121
122 spin_unlock_irqrestore(&queue->irqlock, flags);
123}
124
125static const struct vb2_ops uvc_queue_qops = {
126 .queue_setup = uvc_queue_setup,
127 .buf_prepare = uvc_buffer_prepare,
128 .buf_queue = uvc_buffer_queue,
129 .wait_prepare = vb2_ops_wait_prepare,
130 .wait_finish = vb2_ops_wait_finish,
131};
132
133int uvcg_queue_init(struct uvc_video_queue *queue, struct device *dev, enum v4l2_buf_type type,
134 struct mutex *lock)
135{
136 struct uvc_video *video = container_of(queue, struct uvc_video, queue);
137 struct usb_composite_dev *cdev = video->uvc->func.config->cdev;
138 int ret;
139
140 queue->queue.type = type;
141 queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
142 queue->queue.drv_priv = queue;
143 queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
144 queue->queue.ops = &uvc_queue_qops;
145 queue->queue.lock = lock;
146 if (cdev->gadget->sg_supported) {
147 queue->queue.mem_ops = &vb2_dma_sg_memops;
148 queue->use_sg = 1;
149 } else {
150 queue->queue.mem_ops = &vb2_vmalloc_memops;
151 }
152
153 queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY
154 | V4L2_BUF_FLAG_TSTAMP_SRC_EOF;
155 queue->queue.dev = dev;
156
157 ret = vb2_queue_init(&queue->queue);
158 if (ret)
159 return ret;
160
161 spin_lock_init(&queue->irqlock);
162 INIT_LIST_HEAD(&queue->irqqueue);
163 queue->flags = 0;
164
165 return 0;
166}
167
168/*
169 * Free the video buffers.
170 */
171void uvcg_free_buffers(struct uvc_video_queue *queue)
172{
173 vb2_queue_release(&queue->queue);
174}
175
176/*
177 * Allocate the video buffers.
178 */
179int uvcg_alloc_buffers(struct uvc_video_queue *queue,
180 struct v4l2_requestbuffers *rb)
181{
182 int ret;
183
184 ret = vb2_reqbufs(&queue->queue, rb);
185
186 return ret ? ret : rb->count;
187}
188
189int uvcg_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
190{
191 return vb2_querybuf(&queue->queue, buf);
192}
193
194int uvcg_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
195{
196 return vb2_qbuf(&queue->queue, NULL, buf);
197}
198
199/*
200 * Dequeue a video buffer. If nonblocking is false, block until a buffer is
201 * available.
202 */
203int uvcg_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
204 int nonblocking)
205{
206 return vb2_dqbuf(&queue->queue, buf, nonblocking);
207}
208
209/*
210 * Poll the video queue.
211 *
212 * This function implements video queue polling and is intended to be used by
213 * the device poll handler.
214 */
215__poll_t uvcg_queue_poll(struct uvc_video_queue *queue, struct file *file,
216 poll_table *wait)
217{
218 return vb2_poll(&queue->queue, file, wait);
219}
220
221int uvcg_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
222{
223 return vb2_mmap(&queue->queue, vma);
224}
225
226#ifndef CONFIG_MMU
227/*
228 * Get unmapped area.
229 *
230 * NO-MMU arch need this function to make mmap() work correctly.
231 */
232unsigned long uvcg_queue_get_unmapped_area(struct uvc_video_queue *queue,
233 unsigned long pgoff)
234{
235 return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
236}
237#endif
238
239/*
240 * Cancel the video buffers queue.
241 *
242 * Cancelling the queue marks all buffers on the irq queue as erroneous,
243 * wakes them up and removes them from the queue.
244 *
245 * If the disconnect parameter is set, further calls to uvc_queue_buffer will
246 * fail with -ENODEV.
247 *
248 * This function acquires the irq spinlock and can be called from interrupt
249 * context.
250 */
251void uvcg_queue_cancel(struct uvc_video_queue *queue, int disconnect)
252{
253 struct uvc_buffer *buf;
254 unsigned long flags;
255
256 spin_lock_irqsave(&queue->irqlock, flags);
257 while (!list_empty(&queue->irqqueue)) {
258 buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
259 queue);
260 list_del(&buf->queue);
261 buf->state = UVC_BUF_STATE_ERROR;
262 vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_ERROR);
263 }
264 queue->buf_used = 0;
265
266 /*
267 * This must be protected by the irqlock spinlock to avoid race
268 * conditions between uvc_queue_buffer and the disconnection event that
269 * could result in an interruptible wait in uvc_dequeue_buffer. Do not
270 * blindly replace this logic by checking for the UVC_DEV_DISCONNECTED
271 * state outside the queue code.
272 */
273 if (disconnect)
274 queue->flags |= UVC_QUEUE_DISCONNECTED;
275 spin_unlock_irqrestore(&queue->irqlock, flags);
276}
277
278/*
279 * Enable or disable the video buffers queue.
280 *
281 * The queue must be enabled before starting video acquisition and must be
282 * disabled after stopping it. This ensures that the video buffers queue
283 * state can be properly initialized before buffers are accessed from the
284 * interrupt handler.
285 *
286 * Enabling the video queue initializes parameters (such as sequence number,
287 * sync pattern, ...). If the queue is already enabled, return -EBUSY.
288 *
289 * Disabling the video queue cancels the queue and removes all buffers from
290 * the main queue.
291 *
292 * This function can't be called from interrupt context. Use
293 * uvcg_queue_cancel() instead.
294 */
295int uvcg_queue_enable(struct uvc_video_queue *queue, int enable)
296{
297 unsigned long flags;
298 int ret = 0;
299
300 if (enable) {
301 ret = vb2_streamon(&queue->queue, queue->queue.type);
302 if (ret < 0)
303 return ret;
304
305 queue->sequence = 0;
306 queue->buf_used = 0;
307 queue->flags &= ~UVC_QUEUE_DROP_INCOMPLETE;
308 } else {
309 ret = vb2_streamoff(&queue->queue, queue->queue.type);
310 if (ret < 0)
311 return ret;
312
313 spin_lock_irqsave(&queue->irqlock, flags);
314 INIT_LIST_HEAD(&queue->irqqueue);
315
316 /*
317 * FIXME: We need to clear the DISCONNECTED flag to ensure that
318 * applications will be able to queue buffers for the next
319 * streaming run. However, clearing it here doesn't guarantee
320 * that the device will be reconnected in the meantime.
321 */
322 queue->flags &= ~UVC_QUEUE_DISCONNECTED;
323 spin_unlock_irqrestore(&queue->irqlock, flags);
324 }
325
326 return ret;
327}
328
329/* called with &queue_irqlock held.. */
330void uvcg_complete_buffer(struct uvc_video_queue *queue,
331 struct uvc_buffer *buf)
332{
333 if (queue->flags & UVC_QUEUE_DROP_INCOMPLETE) {
334 queue->flags &= ~UVC_QUEUE_DROP_INCOMPLETE;
335 buf->state = UVC_BUF_STATE_ERROR;
336 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
337 vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_ERROR);
338 return;
339 }
340
341 buf->buf.field = V4L2_FIELD_NONE;
342 buf->buf.sequence = queue->sequence++;
343 buf->buf.vb2_buf.timestamp = ktime_get_ns();
344
345 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
346 vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
347}
348
349struct uvc_buffer *uvcg_queue_head(struct uvc_video_queue *queue)
350{
351 struct uvc_buffer *buf = NULL;
352
353 if (!list_empty(&queue->irqqueue))
354 buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
355 queue);
356
357 return buf;
358}
359
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 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, 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