2 * videobuf2-core.h - Video Buffer 2 Core Framework
4 * Copyright (C) 2010 Samsung Electronics
6 * Author: Pawel Osciak <pawel@osciak.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation.
12 #ifndef _MEDIA_VIDEOBUF2_CORE_H
13 #define _MEDIA_VIDEOBUF2_CORE_H
15 #include <linux/mm_types.h>
16 #include <linux/mutex.h>
17 #include <linux/poll.h>
18 #include <linux/dma-buf.h>
20 #define VB2_MAX_FRAME (32)
21 #define VB2_MAX_PLANES (8)
24 VB2_MEMORY_UNKNOWN
= 0,
26 VB2_MEMORY_USERPTR
= 2,
27 VB2_MEMORY_DMABUF
= 4,
31 struct vb2_fileio_data
;
32 struct vb2_threadio_data
;
35 * struct vb2_mem_ops - memory handling/memory allocator operations
36 * @alloc: allocate video memory and, optionally, allocator private data,
37 * return NULL on failure or a pointer to allocator private,
38 * per-buffer data on success; the returned private structure
39 * will then be passed as buf_priv argument to other ops in this
40 * structure. Additional gfp_flags to use when allocating the
41 * are also passed to this operation. These flags are from the
42 * gfp_flags field of vb2_queue.
43 * @put: inform the allocator that the buffer will no longer be used;
44 * usually will result in the allocator freeing the buffer (if
45 * no other users of this buffer are present); the buf_priv
46 * argument is the allocator private per-buffer structure
47 * previously returned from the alloc callback.
48 * @get_dmabuf: acquire userspace memory for a hardware operation; used for
49 * DMABUF memory types.
50 * @get_userptr: acquire userspace memory for a hardware operation; used for
51 * USERPTR memory types; vaddr is the address passed to the
52 * videobuf layer when queuing a video buffer of USERPTR type;
53 * should return an allocator private per-buffer structure
54 * associated with the buffer on success, NULL on failure;
55 * the returned private structure will then be passed as buf_priv
56 * argument to other ops in this structure.
57 * @put_userptr: inform the allocator that a USERPTR buffer will no longer
59 * @attach_dmabuf: attach a shared struct dma_buf for a hardware operation;
60 * used for DMABUF memory types; alloc_ctx is the alloc context
61 * dbuf is the shared dma_buf; returns NULL on failure;
62 * allocator private per-buffer structure on success;
63 * this needs to be used for further accesses to the buffer.
64 * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
65 * buffer is no longer used; the buf_priv argument is the
66 * allocator private per-buffer structure previously returned
67 * from the attach_dmabuf callback.
68 * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
69 * of dmabuf is informed that this driver is going to use the
71 * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
72 * that this driver is done using the dmabuf for now.
73 * @prepare: called every time the buffer is passed from userspace to the
74 * driver, useful for cache synchronisation, optional.
75 * @finish: called every time the buffer is passed back from the driver
76 * to the userspace, also optional.
77 * @vaddr: return a kernel virtual address to a given memory buffer
78 * associated with the passed private structure or NULL if no
79 * such mapping exists.
80 * @cookie: return allocator specific cookie for a given memory buffer
81 * associated with the passed private structure or NULL if not
83 * @num_users: return the current number of users of a memory buffer;
84 * return 1 if the videobuf layer (or actually the driver using
85 * it) is the only user.
86 * @mmap: setup a userspace mapping for a given memory buffer under
87 * the provided virtual memory region.
89 * Required ops for USERPTR types: get_userptr, put_userptr.
90 * Required ops for MMAP types: alloc, put, num_users, mmap.
91 * Required ops for read/write access types: alloc, put, num_users, vaddr.
92 * Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, map_dmabuf,
96 void *(*alloc
)(void *alloc_ctx
, unsigned long size
,
97 enum dma_data_direction dma_dir
,
99 void (*put
)(void *buf_priv
);
100 struct dma_buf
*(*get_dmabuf
)(void *buf_priv
, unsigned long flags
);
102 void *(*get_userptr
)(void *alloc_ctx
, unsigned long vaddr
,
104 enum dma_data_direction dma_dir
);
105 void (*put_userptr
)(void *buf_priv
);
107 void (*prepare
)(void *buf_priv
);
108 void (*finish
)(void *buf_priv
);
110 void *(*attach_dmabuf
)(void *alloc_ctx
, struct dma_buf
*dbuf
,
112 enum dma_data_direction dma_dir
);
113 void (*detach_dmabuf
)(void *buf_priv
);
114 int (*map_dmabuf
)(void *buf_priv
);
115 void (*unmap_dmabuf
)(void *buf_priv
);
117 void *(*vaddr
)(void *buf_priv
);
118 void *(*cookie
)(void *buf_priv
);
120 unsigned int (*num_users
)(void *buf_priv
);
122 int (*mmap
)(void *buf_priv
, struct vm_area_struct
*vma
);
126 * struct vb2_plane - plane information
127 * @mem_priv: private data with this plane
128 * @dbuf: dma_buf - shared buffer object
129 * @dbuf_mapped: flag to show whether dbuf is mapped or not
130 * @bytesused: number of bytes occupied by data in the plane (payload)
131 * @length: size of this plane (NOT the payload) in bytes
132 * @offset: when memory in the associated struct vb2_buffer is
133 * VB2_MEMORY_MMAP, equals the offset from the start of
134 * the device memory for this plane (or is a "cookie" that
135 * should be passed to mmap() called on the video node)
136 * @userptr: when memory is VB2_MEMORY_USERPTR, a userspace pointer
137 * pointing to this plane
138 * @fd: when memory is VB2_MEMORY_DMABUF, a userspace file
139 * descriptor associated with this plane
140 * @m: Union with memtype-specific data (@offset, @userptr or
142 * @data_offset: offset in the plane to the start of data; usually 0,
143 * unless there is a header in front of the data
144 * Should contain enough information to be able to cover all the fields
145 * of struct v4l2_plane at videodev2.h
149 struct dma_buf
*dbuf
;
150 unsigned int dbuf_mapped
;
151 unsigned int bytesused
;
155 unsigned long userptr
;
158 unsigned int data_offset
;
162 * enum vb2_io_modes - queue access methods
163 * @VB2_MMAP: driver supports MMAP with streaming API
164 * @VB2_USERPTR: driver supports USERPTR with streaming API
165 * @VB2_READ: driver supports read() style access
166 * @VB2_WRITE: driver supports write() style access
167 * @VB2_DMABUF: driver supports DMABUF with streaming API
171 VB2_USERPTR
= (1 << 1),
173 VB2_WRITE
= (1 << 3),
174 VB2_DMABUF
= (1 << 4),
178 * enum vb2_buffer_state - current video buffer state
179 * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control
180 * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf
181 * @VB2_BUF_STATE_PREPARED: buffer prepared in videobuf and by the driver
182 * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver
183 * @VB2_BUF_STATE_REQUEUEING: re-queue a buffer to the driver
184 * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used
185 * in a hardware operation
186 * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but
187 * not yet dequeued to userspace
188 * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer
189 * has ended with an error, which will be reported
190 * to the userspace when it is dequeued
192 enum vb2_buffer_state
{
193 VB2_BUF_STATE_DEQUEUED
,
194 VB2_BUF_STATE_PREPARING
,
195 VB2_BUF_STATE_PREPARED
,
196 VB2_BUF_STATE_QUEUED
,
197 VB2_BUF_STATE_REQUEUEING
,
198 VB2_BUF_STATE_ACTIVE
,
206 * struct vb2_buffer - represents a video buffer
207 * @vb2_queue: the queue to which this driver belongs
208 * @index: id number of the buffer
210 * @memory: the method, in which the actual data is passed
211 * @num_planes: number of planes in the buffer
212 * on an internal driver queue
213 * @planes: private per-plane information; do not change
214 * @timestamp: frame timestamp in ns
217 struct vb2_queue
*vb2_queue
;
221 unsigned int num_planes
;
222 struct vb2_plane planes
[VB2_MAX_PLANES
];
225 /* private: internal use only
227 * state: current buffer state; do not change
228 * queued_entry: entry on the queued buffers list, which holds
229 * all buffers queued from userspace
230 * done_entry: entry on the list that stores all buffers ready
231 * to be dequeued to userspace
233 enum vb2_buffer_state state
;
235 struct list_head queued_entry
;
236 struct list_head done_entry
;
237 #ifdef CONFIG_VIDEO_ADV_DEBUG
239 * Counters for how often these buffer-related ops are
240 * called. Used to check for unbalanced ops.
244 u32 cnt_mem_get_dmabuf
;
245 u32 cnt_mem_get_userptr
;
246 u32 cnt_mem_put_userptr
;
249 u32 cnt_mem_attach_dmabuf
;
250 u32 cnt_mem_detach_dmabuf
;
251 u32 cnt_mem_map_dmabuf
;
252 u32 cnt_mem_unmap_dmabuf
;
255 u32 cnt_mem_num_users
;
264 /* This counts the number of calls to vb2_buffer_done() */
270 * struct vb2_ops - driver-specific callbacks
272 * @queue_setup: called from VIDIOC_REQBUFS and VIDIOC_CREATE_BUFS
273 * handlers before memory allocation. It can be called
274 * twice: if the original number of requested buffers
275 * could not be allocated, then it will be called a
276 * second time with the actually allocated number of
277 * buffers to verify if that is OK.
278 * The driver should return the required number of buffers
279 * in *num_buffers, the required number of planes per
280 * buffer in *num_planes, the size of each plane should be
281 * set in the sizes[] array and optional per-plane
282 * allocator specific context in the alloc_ctxs[] array.
283 * When called from VIDIOC_REQBUFS, *num_planes == 0, the
284 * driver has to use the currently configured format to
285 * determine the plane sizes and *num_buffers is the total
286 * number of buffers that are being allocated. When called
287 * from VIDIOC_CREATE_BUFS, *num_planes != 0 and it
288 * describes the requested number of planes and sizes[]
289 * contains the requested plane sizes. If either
290 * *num_planes or the requested sizes are invalid callback
291 * must return -EINVAL. In this case *num_buffers are
292 * being allocated additionally to q->num_buffers.
293 * @wait_prepare: release any locks taken while calling vb2 functions;
294 * it is called before an ioctl needs to wait for a new
295 * buffer to arrive; required to avoid a deadlock in
296 * blocking access type.
297 * @wait_finish: reacquire all locks released in the previous callback;
298 * required to continue operation after sleeping while
299 * waiting for a new buffer to arrive.
300 * @buf_init: called once after allocating a buffer (in MMAP case)
301 * or after acquiring a new USERPTR buffer; drivers may
302 * perform additional buffer-related initialization;
303 * initialization failure (return != 0) will prevent
304 * queue setup from completing successfully; optional.
305 * @buf_prepare: called every time the buffer is queued from userspace
306 * and from the VIDIOC_PREPARE_BUF ioctl; drivers may
307 * perform any initialization required before each
308 * hardware operation in this callback; drivers can
309 * access/modify the buffer here as it is still synced for
310 * the CPU; drivers that support VIDIOC_CREATE_BUFS must
311 * also validate the buffer size; if an error is returned,
312 * the buffer will not be queued in driver; optional.
313 * @buf_finish: called before every dequeue of the buffer back to
314 * userspace; the buffer is synced for the CPU, so drivers
315 * can access/modify the buffer contents; drivers may
316 * perform any operations required before userspace
317 * accesses the buffer; optional. The buffer state can be
318 * one of the following: DONE and ERROR occur while
319 * streaming is in progress, and the PREPARED state occurs
320 * when the queue has been canceled and all pending
321 * buffers are being returned to their default DEQUEUED
322 * state. Typically you only have to do something if the
323 * state is VB2_BUF_STATE_DONE, since in all other cases
324 * the buffer contents will be ignored anyway.
325 * @buf_cleanup: called once before the buffer is freed; drivers may
326 * perform any additional cleanup; optional.
327 * @start_streaming: called once to enter 'streaming' state; the driver may
328 * receive buffers with @buf_queue callback before
329 * @start_streaming is called; the driver gets the number
330 * of already queued buffers in count parameter; driver
331 * can return an error if hardware fails, in that case all
332 * buffers that have been already given by the @buf_queue
333 * callback are to be returned by the driver by calling
334 * @vb2_buffer_done(VB2_BUF_STATE_QUEUED).
335 * If you need a minimum number of buffers before you can
336 * start streaming, then set @min_buffers_needed in the
337 * vb2_queue structure. If that is non-zero then
338 * start_streaming won't be called until at least that
339 * many buffers have been queued up by userspace.
340 * @stop_streaming: called when 'streaming' state must be disabled; driver
341 * should stop any DMA transactions or wait until they
342 * finish and give back all buffers it got from buf_queue()
343 * callback by calling @vb2_buffer_done() with either
344 * VB2_BUF_STATE_DONE or VB2_BUF_STATE_ERROR; may use
345 * vb2_wait_for_all_buffers() function
346 * @buf_queue: passes buffer vb to the driver; driver may start
347 * hardware operation on this buffer; driver should give
348 * the buffer back by calling vb2_buffer_done() function;
349 * it is allways called after calling STREAMON ioctl;
350 * might be called before start_streaming callback if user
351 * pre-queued buffers before calling STREAMON.
354 int (*queue_setup
)(struct vb2_queue
*q
,
355 unsigned int *num_buffers
, unsigned int *num_planes
,
356 unsigned int sizes
[], void *alloc_ctxs
[]);
358 void (*wait_prepare
)(struct vb2_queue
*q
);
359 void (*wait_finish
)(struct vb2_queue
*q
);
361 int (*buf_init
)(struct vb2_buffer
*vb
);
362 int (*buf_prepare
)(struct vb2_buffer
*vb
);
363 void (*buf_finish
)(struct vb2_buffer
*vb
);
364 void (*buf_cleanup
)(struct vb2_buffer
*vb
);
366 int (*start_streaming
)(struct vb2_queue
*q
, unsigned int count
);
367 void (*stop_streaming
)(struct vb2_queue
*q
);
369 void (*buf_queue
)(struct vb2_buffer
*vb
);
373 int (*fill_user_buffer
)(struct vb2_buffer
*vb
, void *pb
);
374 int (*fill_vb2_buffer
)(struct vb2_buffer
*vb
, const void *pb
,
375 struct vb2_plane
*planes
);
376 int (*set_timestamp
)(struct vb2_buffer
*vb
, const void *pb
);
380 * struct vb2_queue - a videobuf queue
382 * @type: private buffer type whose content is defined by the vb2-core
383 * caller. For example, for V4L2, it should match
384 * the V4L2_BUF_TYPE_* in include/uapi/linux/videodev2.h
385 * @io_modes: supported io methods (see vb2_io_modes enum)
386 * @fileio_read_once: report EOF after reading the first buffer
387 * @fileio_write_immediately: queue buffer after each write() call
388 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver
389 * @lock: pointer to a mutex that protects the vb2_queue struct. The
390 * driver can set this to a mutex to let the v4l2 core serialize
391 * the queuing ioctls. If the driver wants to handle locking
392 * itself, then this should be set to NULL. This lock is not used
393 * by the videobuf2 core API.
394 * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle
395 * that called reqbufs, create_buffers or started fileio.
396 * This field is not used by the videobuf2 core API, but it allows
397 * drivers to easily associate an owner filehandle with the queue.
398 * @ops: driver-specific callbacks
399 * @mem_ops: memory allocator specific callbacks
400 * @buf_ops: callbacks to deliver buffer information
401 * between user-space and kernel-space
402 * @drv_priv: driver private data
403 * @buf_struct_size: size of the driver-specific buffer structure;
404 * "0" indicates the driver doesn't want to use a custom buffer
405 * structure type. for example, sizeof(struct vb2_v4l2_buffer)
406 * will be used for v4l2.
407 * @timestamp_flags: Timestamp flags; V4L2_BUF_FLAG_TIMESTAMP_* and
408 * V4L2_BUF_FLAG_TSTAMP_SRC_*
409 * @gfp_flags: additional gfp flags used when allocating the buffers.
410 * Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32
411 * to force the buffer allocation to a specific memory zone.
412 * @min_buffers_needed: the minimum number of buffers needed before
413 * start_streaming() can be called. Used when a DMA engine
414 * cannot be started unless at least this number of buffers
415 * have been queued into the driver.
418 * Private elements (won't appear at the DocBook):
419 * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped
420 * @memory: current memory type used
421 * @bufs: videobuf buffer structures
422 * @num_buffers: number of allocated/used buffers
423 * @queued_list: list of buffers currently queued from userspace
424 * @queued_count: number of buffers queued and ready for streaming.
425 * @owned_by_drv_count: number of buffers owned by the driver
426 * @done_list: list of buffers ready to be dequeued to userspace
427 * @done_lock: lock to protect done_list list
428 * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued
429 * @alloc_ctx: memory type/allocator-specific contexts for each plane
430 * @streaming: current streaming state
431 * @start_streaming_called: start_streaming() was called successfully and we
433 * @error: a fatal error occurred on the queue
434 * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
435 * buffers. Only set for capture queues if qbuf has not yet been
436 * called since poll() needs to return POLLERR in that situation.
437 * @is_multiplanar: set if buffer type is multiplanar
438 * @is_output: set if buffer type is output
439 * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
440 * last decoded buffer was already dequeued. Set for capture queues
441 * when a buffer with the V4L2_BUF_FLAG_LAST is dequeued.
442 * @fileio: file io emulator internal data, used only if emulator is active
443 * @threadio: thread io internal data, used only if thread is active
447 unsigned int io_modes
;
448 unsigned fileio_read_once
:1;
449 unsigned fileio_write_immediately
:1;
450 unsigned allow_zero_bytesused
:1;
455 const struct vb2_ops
*ops
;
456 const struct vb2_mem_ops
*mem_ops
;
457 const struct vb2_buf_ops
*buf_ops
;
460 unsigned int buf_struct_size
;
463 u32 min_buffers_needed
;
465 /* private: internal use only */
466 struct mutex mmap_lock
;
468 struct vb2_buffer
*bufs
[VB2_MAX_FRAME
];
469 unsigned int num_buffers
;
471 struct list_head queued_list
;
472 unsigned int queued_count
;
474 atomic_t owned_by_drv_count
;
475 struct list_head done_list
;
476 spinlock_t done_lock
;
477 wait_queue_head_t done_wq
;
479 void *alloc_ctx
[VB2_MAX_PLANES
];
480 unsigned int plane_sizes
[VB2_MAX_PLANES
];
482 unsigned int streaming
:1;
483 unsigned int start_streaming_called
:1;
484 unsigned int error
:1;
485 unsigned int waiting_for_buffers
:1;
486 unsigned int is_multiplanar
:1;
487 unsigned int is_output
:1;
488 unsigned int last_buffer_dequeued
:1;
490 struct vb2_fileio_data
*fileio
;
491 struct vb2_threadio_data
*threadio
;
493 #ifdef CONFIG_VIDEO_ADV_DEBUG
495 * Counters for how often these queue-related ops are
496 * called. Used to check for unbalanced ops.
499 u32 cnt_wait_prepare
;
501 u32 cnt_start_streaming
;
502 u32 cnt_stop_streaming
;
506 void *vb2_plane_vaddr(struct vb2_buffer
*vb
, unsigned int plane_no
);
507 void *vb2_plane_cookie(struct vb2_buffer
*vb
, unsigned int plane_no
);
509 void vb2_buffer_done(struct vb2_buffer
*vb
, enum vb2_buffer_state state
);
510 void vb2_discard_done(struct vb2_queue
*q
);
511 int vb2_wait_for_all_buffers(struct vb2_queue
*q
);
513 int vb2_core_querybuf(struct vb2_queue
*q
, unsigned int index
, void *pb
);
514 int vb2_core_reqbufs(struct vb2_queue
*q
, enum vb2_memory memory
,
515 unsigned int *count
);
516 int vb2_core_create_bufs(struct vb2_queue
*q
, enum vb2_memory memory
,
517 unsigned int *count
, unsigned requested_planes
,
518 const unsigned int requested_sizes
[]);
519 int vb2_core_prepare_buf(struct vb2_queue
*q
, unsigned int index
, void *pb
);
520 int vb2_core_qbuf(struct vb2_queue
*q
, unsigned int index
, void *pb
);
521 int vb2_core_dqbuf(struct vb2_queue
*q
, void *pb
, bool nonblocking
);
523 int vb2_core_streamon(struct vb2_queue
*q
, unsigned int type
);
524 int vb2_core_streamoff(struct vb2_queue
*q
, unsigned int type
);
526 int vb2_core_expbuf(struct vb2_queue
*q
, int *fd
, unsigned int type
,
527 unsigned int index
, unsigned int plane
, unsigned int flags
);
529 int vb2_core_queue_init(struct vb2_queue
*q
);
530 void vb2_core_queue_release(struct vb2_queue
*q
);
532 void vb2_queue_error(struct vb2_queue
*q
);
534 int vb2_mmap(struct vb2_queue
*q
, struct vm_area_struct
*vma
);
536 unsigned long vb2_get_unmapped_area(struct vb2_queue
*q
,
540 unsigned long flags
);
544 * vb2_is_streaming() - return streaming status of the queue
547 static inline bool vb2_is_streaming(struct vb2_queue
*q
)
553 * vb2_fileio_is_active() - return true if fileio is active.
556 * This returns true if read() or write() is used to stream the data
557 * as opposed to stream I/O. This is almost never an important distinction,
558 * except in rare cases. One such case is that using read() or write() to
559 * stream a format using V4L2_FIELD_ALTERNATE is not allowed since there
560 * is no way you can pass the field information of each buffer to/from
561 * userspace. A driver that supports this field format should check for
562 * this in the queue_setup op and reject it if this function returns true.
564 static inline bool vb2_fileio_is_active(struct vb2_queue
*q
)
570 * vb2_is_busy() - return busy status of the queue
573 * This function checks if queue has any buffers allocated.
575 static inline bool vb2_is_busy(struct vb2_queue
*q
)
577 return (q
->num_buffers
> 0);
581 * vb2_get_drv_priv() - return driver private data associated with the queue
584 static inline void *vb2_get_drv_priv(struct vb2_queue
*q
)
590 * vb2_set_plane_payload() - set bytesused for the plane plane_no
591 * @vb: buffer for which plane payload should be set
592 * @plane_no: plane number for which payload should be set
593 * @size: payload in bytes
595 static inline void vb2_set_plane_payload(struct vb2_buffer
*vb
,
596 unsigned int plane_no
, unsigned long size
)
598 if (plane_no
< vb
->num_planes
)
599 vb
->planes
[plane_no
].bytesused
= size
;
603 * vb2_get_plane_payload() - get bytesused for the plane plane_no
604 * @vb: buffer for which plane payload should be set
605 * @plane_no: plane number for which payload should be set
607 static inline unsigned long vb2_get_plane_payload(struct vb2_buffer
*vb
,
608 unsigned int plane_no
)
610 if (plane_no
< vb
->num_planes
)
611 return vb
->planes
[plane_no
].bytesused
;
616 * vb2_plane_size() - return plane size in bytes
617 * @vb: buffer for which plane size should be returned
618 * @plane_no: plane number for which size should be returned
620 static inline unsigned long
621 vb2_plane_size(struct vb2_buffer
*vb
, unsigned int plane_no
)
623 if (plane_no
< vb
->num_planes
)
624 return vb
->planes
[plane_no
].length
;
629 * vb2_start_streaming_called() - return streaming status of driver
632 static inline bool vb2_start_streaming_called(struct vb2_queue
*q
)
634 return q
->start_streaming_called
;
638 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue
641 static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue
*q
)
643 q
->last_buffer_dequeued
= false;
646 #endif /* _MEDIA_VIDEOBUF2_CORE_H */