【genius_platform软件平台开发】第五十九讲：Linux系统之V4L2视频驱动-VIDIOC_QUERYBUF查询缓存信息
VIDIOC_QUERYBUF查询缓存信息代码详解
- 1. 概述
- 2 应用层
-
- 2.1 struct v4l2_buffer结构体
- 3. 驱动层
-
- 3.1 vb2_ioctl_querybuf函数
- 3.2 vb2_querybuf函数
- 3.3 __fill_v4l2_buffer函数
- 3.4 enum vb2_buffer_state枚举
- 3.5 enum vb2_io_modes枚举
- 3.6 struct vb2_plane结构体
- 3.7 struct vb2_buffer结构体（*）
- 3.8 struct vb2_ops结构体
- 3.9 struct vb2_buf_ops 结构体
- 3.10 struct vb2_queue 结构体
1. 概述
VIDIOC_QUERYBUF主要作用是查询分配好的buffer信息在内核空间中的长度length和偏移量offset.查询已经分配好的V4L2视频缓冲区的相关信息,包括缓冲区的使用状态、在内核空间的偏移地址、缓冲区长度等,然后应用程序根据这些信息使用mmap把内核空间地址映射到用户空间。
2 应用层
2.1 struct v4l2_buffer结构体
struct v4l2_buffer
{
__u32 index; //buffer 序号
enum v4l2_buf_type type; //buffer 类型
__u32 byteused; //buffer 中已使用的字节数
__u32 flags; // 区分是MMAP 还是USERPTR
enum v4l2_field field;
struct timeval timestamp;// 获取第一个字节时的系统时间
struct v4l2_timecode timecode;
__u32 sequence; // 队列中的序号
enum v4l2_memory memory;//IO 方式，被应用程序设置
union m
{
__u32 offset;// 缓冲帧地址，只对MMAP 有效
unsigned long userptr;
};
__u32 length;// 缓冲帧长度
__u32 input;
__u32 reserved;
};
v4l2_buffer buf;
buf.index = i;
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
ret = ioctl(fd , VIDIOC_QUERYBUF, &buf);
if(ret < 0) {
LOG("VIDIOC_QUERYBUF (%d) failed (%d)\n", i, ret);
return ret;
3. 驱动层
3.1 vb2_ioctl_querybuf函数
int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
struct video_device *vdev = video_devdata(file);
/* No need to call vb2_queue_is_busy(), anyone can query buffers. */
return vb2_querybuf(vdev->queue, p);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
3.2 vb2_querybuf函数
int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
{
struct vb2_buffer *vb;
// 取出 buf
vb = q->bufs[b->index];
// 将 buf 信息写回用户空间传递的 b
return __fill_v4l2_buffer(vb, b);
}
3.3 __fill_v4l2_buffer函数
/**
* __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
* returned to userspace
*/
static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
{
struct v4l2_buffer *b = pb;
/*
* 对于vb2_v4l2_buffer好像是第一次见到，这里分析一下来源
* 先说一下这个函数的2个参数
* vb是来源于bufs[index]，申请buffer的时候填充的
* pb则是来自于用户空间的地址
* vbuf = to_vb2_v4l2_buffer(vb)
* 说明和vb有关系
* __vb2_queue_alloc中vb创建如下
* vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
* 而q->buf_struct_size值在
* vb2_queue_init
* if (q->buf_struct_size == 0)
* q->buf_struct_size = sizeof(struct vb2_v4l2_buffer);
* 也就是不为0的时候，这里会赋值
* 但是vivi驱动中已经对其赋值了
* q->buf_struct_size = sizeof(struct vivi_buffer);
* 这样就找到了，对应的vb2_v4l2_buffer
* 实际看vivi_buffer，
* struct vivi_buffer {
* struct vb2_buffer vb;
* struct list_head list;
* struct vivi_fmt *fmt;
* }
* 没看到vb2_v4l2_buffer相关的东西
* 于是去看最新的vivi驱动代码，如下
* struct vivid_buffer {
* struct vb2_v4l2_buffer vb;
* struct list_head list;
* };
* 这里就可以看到vb2_v4l2_buffer的来源了
* 其实主要原因还是vivi驱动太老，linux内核太新不匹配造成的
* */
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
struct vb2_queue *q = vb->vb2_queue;
unsigned int plane;
// 直接填充数据成员信息
/* Copy back data such as timestamp, flags, etc. */
b->index = vb->index;
b->type = vb->type;
b->memory = vb->memory;
b->bytesused = 0;
b->flags = vbuf->flags;
b->field = vbuf->field;
b->timestamp = ns_to_timeval(vb->timestamp);
b->timecode = vbuf->timecode;
b->sequence = vbuf->sequence;
b->reserved2 = 0;
b->reserved = 0;
// 多平面视频格式暂不做解释，还没细研究!!!
if (q->is_multiplanar) {
/*
* Fill in plane-related data if userspace provided an array
* for it. The caller has already verified memory and size.
*/
b->length = vb->num_planes;
for (plane = 0; plane < vb->num_planes; ++plane) {
struct v4l2_plane *pdst = &b->m.planes[plane];
struct vb2_plane *psrc = &vb->planes[plane];
pdst->bytesused = psrc->bytesused;
pdst->length = psrc->length;
if (q->memory == VB2_MEMORY_MMAP)
pdst->m.mem_offset = psrc->m.offset;
else if (q->memory == VB2_MEMORY_USERPTR)
pdst->m.userptr = psrc->m.userptr;
else if (q->memory == VB2_MEMORY_DMABUF)
pdst->m.fd = psrc->m.fd;
pdst->data_offset = psrc->data_offset;
memset(pdst->reserved, 0, sizeof(pdst->reserved));
}
} else {
/*
* length: 平面的大小，可能与真实的数据帧大小不一致，驱动为了page对齐会变大
* byteused: 帧数据的大小，这里为0，后面的分析中可以看到更新
* 应用代码中有时候可能会用length代表帧数据的大小，这个值有可能是不准确的
* 比如帧大小是4812Byte，那么驱动中有可能为了方便，将length设置为5000
* 所以最好使用byteused
*/
/*
* We use length and offset in v4l2_planes array even for
* single-planar buffers, but userspace does not.
*/
b->length = vb->planes[0].length;
b->bytesused = vb->planes[0].bytesused;
if (q->memory == VB2_MEMORY_MMAP)
b->m.offset = vb->planes[0].m.offset;
else if (q->memory == VB2_MEMORY_USERPTR)
b->m.userptr = vb->planes[0].m.userptr;
else if (q->memory == VB2_MEMORY_DMABUF)
b->m.fd = vb->planes[0].m.fd;
}
/*
* Clear any buffer state related flags.
*/
b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;
if (!q->copy_timestamp) {
/*
* For non-COPY timestamps, drop timestamp source bits
* and obtain the timestamp source from the queue.
*/
b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
}
/*
* 对于vb->state的值
* 在使用reqbuf的时候VIDIOC_REQBUFS，看上一篇
* vb->state = VB2_BUF_STATE_DEQUEUED
* 表示该buffer在用户空间控制，直接break
*/
switch (vb->state) {
case VB2_BUF_STATE_QUEUED:
case VB2_BUF_STATE_ACTIVE:
b->flags |= V4L2_BUF_FLAG_QUEUED;
break;
case VB2_BUF_STATE_ERROR:
b->flags |= V4L2_BUF_FLAG_ERROR;
/* fall through */
case VB2_BUF_STATE_DONE:
b->flags |= V4L2_BUF_FLAG_DONE;
break;
case VB2_BUF_STATE_PREPARED:
b->flags |= V4L2_BUF_FLAG_PREPARED;
break;
case VB2_BUF_STATE_PREPARING:
case VB2_BUF_STATE_DEQUEUED:
case VB2_BUF_STATE_REQUEUEING:
/* nothing */
break;
}
if (vb2_buffer_in_use(q, vb))
b->flags |= V4L2_BUF_FLAG_MAPPED;
if (!q->is_output &&
b->flags & V4L2_BUF_FLAG_DONE &&
b->flags & V4L2_BUF_FLAG_LAST)
q->last_buffer_dequeued = true;
}
3.4 enum vb2_buffer_state枚举
/**
* enum vb2_buffer_state - current video buffer state
* @VB2_BUF_STATE_DEQUEUED: buffer under userspace control
* @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf
* @VB2_BUF_STATE_PREPARED: buffer prepared in videobuf and by the driver
* @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver
* @VB2_BUF_STATE_REQUEUEING: re-queue a buffer to the driver
* @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used
* in a hardware operation
* @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but
* not yet dequeued to userspace
* @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer
* has ended with an error, which will be reported
* to the userspace when it is dequeued
*/
enum vb2_buffer_state {
VB2_BUF_STATE_DEQUEUED,
VB2_BUF_STATE_PREPARING,
VB2_BUF_STATE_PREPARED,
VB2_BUF_STATE_QUEUED,
VB2_BUF_STATE_REQUEUEING,
VB2_BUF_STATE_ACTIVE,
VB2_BUF_STATE_DONE,
VB2_BUF_STATE_ERROR,
};
3.5 enum vb2_io_modes枚举
/**
* enum vb2_io_modes - queue access methods
* @VB2_MMAP: driver supports MMAP with streaming API
* @VB2_USERPTR: driver supports USERPTR with streaming API
* @VB2_READ: driver supports read() style access
* @VB2_WRITE: driver supports write() style access
* @VB2_DMABUF: driver supports DMABUF with streaming API
*/
enum vb2_io_modes {
VB2_MMAP = (1 << 0),
VB2_USERPTR = (1 << 1),
VB2_READ = (1 << 2),
VB2_WRITE = (1 << 3),
VB2_DMABUF = (1 << 4),
}
3.6 struct vb2_plane结构体
/**
* struct vb2_plane - plane information
* @mem_priv: private data with this plane
* @dbuf: dma_buf - shared buffer object
* @dbuf_mapped: flag to show whether dbuf is mapped or not
* @bytesused: number of bytes occupied by data in the plane (payload)
* @length: size of this plane (NOT the payload) in bytes
* @min_length: minimum required size of this plane (NOT the payload) in bytes.
* @length is always greater or equal to @min_length.
* @offset: when memory in the associated struct vb2_buffer is
* VB2_MEMORY_MMAP, equals the offset from the start of
* the device memory for this plane (or is a "cookie" that
* should be passed to mmap() called on the video node)
* @userptr: when memory is VB2_MEMORY_USERPTR, a userspace pointer
* pointing to this plane
* @fd: when memory is VB2_MEMORY_DMABUF, a userspace file
* descriptor associated with this plane
* @m: Union with memtype-specific data (@offset, @userptr or
* @fd).
* @data_offset: offset in the plane to the start of data; usually 0,
* unless there is a header in front of the data
* Should contain enough information to be able to cover all the fields
89,2 8%
* unless there is a header in front of the data
* Should contain enough information to be able to cover all the fields
* of struct v4l2_plane at videodev2.h
*/
struct vb2_plane {
void *mem_priv;
struct dma_buf *dbuf;
unsigned int dbuf_mapped;
unsigned int bytesused;
unsigned int length;
unsigned int min_length;
union {
unsigned int offset;
unsigned long userptr;
int fd;
} m;
unsigned int data_offset;
};
3.7 struct vb2_buffer结构体（*）
* struct vb2_buffer - represents a video buffer
* @vb2_queue: the queue to which this driver belongs
* @index: id number of the buffer
* @type: buffer type
* @memory: the method, in which the actual data is passed
* @num_planes: number of planes in the buffer
* on an internal driver queue
* @planes: private per-plane information; do not change
* @timestamp: frame timestamp in ns
*/
struct vb2_buffer {
struct vb2_queue *vb2_queue;
unsigned int index;
unsigned int type;
unsigned int memory;
unsigned int num_planes;
struct vb2_plane planes[VB2_MAX_PLANES];
u64 timestamp;
/* private: internal use only
*
* state: current buffer state; do not change
* queued_entry: entry on the queued buffers list, which holds
* all buffers queued from userspace
* done_entry: entry on the list that stores all buffers ready
* to be dequeued to userspace
*/
enum vb2_buffer_state state;
struct list_head queued_entry;
struct list_head done_entry;
#ifdef CONFIG_VIDEO_ADV_DEBUG
/*
* Counters for how often these buffer-related ops are
* called. Used to check for unbalanced ops.
*/
u32 cnt_mem_alloc;
u32 cnt_mem_put;
u32 cnt_mem_get_dmabuf;
u32 cnt_mem_get_userptr;
u32 cnt_mem_put_userptr;
u32 cnt_mem_prepare;
u32 cnt_mem_finish;
u32 cnt_mem_attach_dmabuf;
u32 cnt_mem_detach_dmabuf;
u32 cnt_mem_map_dmabuf;
u32 cnt_mem_unmap_dmabuf;
u32 cnt_mem_vaddr;
u32 cnt_mem_cookie;
u32 cnt_mem_num_users;
u32 cnt_mem_mmap;
u32 cnt_buf_init;
u32 cnt_buf_prepare;
u32 cnt_buf_finish;
u32 cnt_buf_cleanup;
u32 cnt_buf_queue;
/* This counts the number of calls to vb2_buffer_done() */
u32 cnt_buf_done;
#endif
};
3.8 struct vb2_ops结构体
/**
* struct vb2_ops - driver-specific callbacks
*
* @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS()
* handlers before memory allocation. It can be called
* twice: if the original number of requested buffers
* could not be allocated, then it will be called a
* second time with the actually allocated number of
* buffers to verify if that is OK.
* The driver should return the required number of buffers
* in \*num_buffers, the required number of planes per
* buffer in \*num_planes, the size of each plane should be
* set in the sizes\[\] array and optional per-plane
* allocator specific device in the alloc_devs\[\] array.
* When called from VIDIOC_REQBUFS(), \*num_planes == 0,
* the driver has to use the currently configured format to
* determine the plane sizes and \*num_buffers is the total
* number of buffers that are being allocated. When called
* from VIDIOC_CREATE_BUFS(), \*num_planes != 0 and it
* describes the requested number of planes and sizes\[\]
* contains the requested plane sizes. In this case
* \*num_buffers are being allocated additionally to
* q->num_buffers. If either \*num_planes or the requested
* sizes are invalid callback must return %-EINVAL.
* @wait_prepare: release any locks taken while calling vb2 functions;
* it is called before an ioctl needs to wait for a new
* buffer to arrive; required to avoid a deadlock in
* blocking access type.
* @wait_finish: reacquire all locks released in the previous callback;
* required to continue operation after sleeping while
* waiting for a new buffer to arrive.
* @buf_init: called once after allocating a buffer (in MMAP case)
* or after acquiring a new USERPTR buffer; drivers may
* perform additional buffer-related initialization;
* initialization failure (return != 0) will prevent
* queue setup from completing successfully; optional.
* @buf_prepare: called every time the buffer is queued from userspace
* and from the VIDIOC_PREPARE_BUF() ioctl; drivers may
* perform any initialization required before each
* hardware operation in this callback; drivers can
* access/modify the buffer here as it is still synced for
* the CPU; drivers that support VIDIOC_CREATE_BUFS() must
* also validate the buffer size; if an error is returned,
* the buffer will not be queued in driver; optional.
* @buf_finish: called before every dequeue of the buffer back to
* userspace; the buffer is synced for the CPU, so drivers
* can access/modify the buffer contents; drivers may
* perform any operations required before userspace
* accesses the buffer; optional. The buffer state can be
* one of the following: %DONE and %ERROR occur while
* streaming is in progress, and the %PREPARED state occurs
* when the queue has been canceled and all pending
* buffers are being returned to their default %DEQUEUED
* state. Typically you only have to do something if the
* state is %VB2_BUF_STATE_DONE, since in all other cases
* the buffer contents will be ignored anyway.
* @buf_cleanup: called once before the buffer is freed; drivers may
* perform any additional cleanup; optional.
* @start_streaming: called once to enter 'streaming' state; the driver may
* receive buffers with @buf_queue callback
* before @start_streaming is called; the driver gets the
* number of already queued buffers in count parameter;
* driver can return an error if hardware fails, in that
* case all buffers that have been already given by
* the @buf_queue callback are to be returned by the driver
* by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED.
* If you need a minimum number of buffers before you can
* start streaming, then set @min_buffers_needed in the
* vb2_queue structure. If that is non-zero then
* @start_streaming won't be called until at least that
* many buffers have been queued up by userspace.
* @stop_streaming: called when 'streaming' state must be disabled; driver
* should stop any DMA transactions or wait until they
* finish and give back all buffers it got from &buf_queue
* callback by calling vb2_buffer_done() with either
* %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use
* vb2_wait_for_all_buffers() function
* @buf_queue: passes buffer vb to the driver; driver may start
* hardware operation on this buffer; driver should give
* the buffer back by calling vb2_buffer_done() function;
* it is allways called after calling VIDIOC_STREAMON()
* ioctl; might be called before @start_streaming callback
* if user pre-queued buffers before calling
* VIDIOC_STREAMON().
*/
struct vb2_ops {
int (*queue_setup)(struct vb2_queue *q,
unsigned int *num_buffers, unsigned int *num_planes,
unsigned int sizes[], struct device *alloc_devs[]);
void (*wait_prepare)(struct vb2_queue *q);
void (*wait_finish)(struct vb2_queue *q);
int (*buf_init)(struct vb2_buffer *vb);
int (*buf_prepare)(struct vb2_buffer *vb);
void (*buf_finish)(struct vb2_buffer *vb);
void (*buf_cleanup)(struct vb2_buffer *vb);
int (*start_streaming)(struct vb2_queue *q, unsigned int count);
void (*stop_streaming)(struct vb2_queue *q);
void (*buf_queue)(struct vb2_buffer *vb);
};
3.9 struct vb2_buf_ops 结构体
/**
* struct vb2_buf_ops - driver-specific callbacks
*
* @verify_planes_array: Verify that a given user space structure contains
* enough planes for the buffer. This is called
* for each dequeued buffer.
* @fill_user_buffer: given a vb2_buffer fill in the userspace structure.
* For V4L2 this is a struct v4l2_buffer.
* @fill_vb2_buffer: given a userspace structure, fill in the vb2_buffer.
* If the userspace structure is invalid, then this op
* will return an error.
* @copy_timestamp: copy the timestamp from a userspace structure to
* the vb2_buffer struct.
*/
struct vb2_buf_ops {
int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb,
struct vb2_plane *planes);
void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb);
};
3.10 struct vb2_queue 结构体
/**
* struct vb2_queue - a videobuf queue
*
* @type: private buffer type whose content is defined by the vb2-core
* caller. For example, for V4L2, it should match
* the types defined on enum &v4l2_buf_type
* @io_modes: supported io methods (see vb2_io_modes enum)
* @dev: device to use for the default allocation context if the driver
* doesn't fill in the @alloc_devs array.
* @dma_attrs: DMA attributes to use for the DMA.
* @bidirectional: when this flag is set the DMA direction for the buffers of
* this queue will be overridden with DMA_BIDIRECTIONAL direction.
* This is useful in cases where the hardware (firmware) writes to
* a buffer which is mapped as read (DMA_TO_DEVICE), or reads from
* buffer which is mapped for write (DMA_FROM_DEVICE) in order
* to satisfy some internal hardware restrictions or adds a padding
* needed by the processing algorithm. In case the DMA mapping is
* not bidirectional but the hardware (firmware) trying to access
* the buffer (in the opposite direction) this could lead to an
* IOMMU protection faults.
* @fileio_read_once: report EOF after reading the first buffer
* @fileio_write_immediately: queue buffer after each write() call
* @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver
* @quirk_poll_must_check_waiting_for_buffers: Return POLLERR at poll when QBUF
* has not been called. This is a vb1 idiom that has been adopted
* also by vb2.
* @lock: pointer to a mutex that protects the vb2_queue struct. The
* driver can set this to a mutex to let the v4l2 core serialize
* the queuing ioctls. If the driver wants to handle locking
* itself, then this should be set to NULL. This lock is not used
* by the videobuf2 core API.
* @owner: The filehandle that 'owns' the buffers, i.e. the filehandle
* that called reqbufs, create_buffers or started fileio.
* This field is not used by the videobuf2 core API, but it allows
* drivers to easily associate an owner filehandle with the queue.
* @ops: driver-specific callbacks
* @mem_ops: memory allocator specific callbacks
* @buf_ops: callbacks to deliver buffer information
* between user-space and kernel-space
* @drv_priv: driver private data
* @buf_struct_size: size of the driver-specific buffer structure;
* "0" indicates the driver doesn't want to use a custom buffer
* structure type. for example, sizeof(struct vb2_v4l2_buffer)
* will be used for v4l2.
* @timestamp_flags: Timestamp flags; V4L2_BUF_FLAG_TIMESTAMP_* and
* V4L2_BUF_FLAG_TSTAMP_SRC_*
* @gfp_flags: additional gfp flags used when allocating the buffers.
* Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32
* to force the buffer allocation to a specific memory zone.
* @min_buffers_needed: the minimum number of buffers needed before
* @start_streaming can be called. Used when a DMA engine
* cannot be started unless at least this number of buffers
* have been queued into the driver.
*/
/*
* Private elements (won't appear at the uAPI book):
* @mmap_lock: private mutex used when buffers are allocated/freed/mmapped
* @memory: current memory type used
* @dma_dir: DMA mapping direction.
* @bufs: videobuf buffer structures
* @num_buffers: number of allocated/used buffers
* @queued_list: list of buffers currently queued from userspace
* @queued_count: number of buffers queued and ready for streaming.
* @owned_by_drv_count: number of buffers owned by the driver
* @done_list: list of buffers ready to be dequeued to userspace
* @done_lock: lock to protect done_list list
* @done_wq: waitqueue for processes waiting for buffers ready to be dequeued
* @alloc_devs: memory type/allocator-specific per-plane device
* @streaming: current streaming state
* @start_streaming_called: @start_streaming was called successfully and we
* started streaming.
* @error: a fatal error occurred on the queue
* @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
* buffers. Only set for capture queues if qbuf has not yet been
* called since poll() needs to return POLLERR in that situation.
* @is_multiplanar: set if buffer type is multiplanar
* @is_output: set if buffer type is output
* @copy_timestamp: set if vb2-core should set timestamps
* @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
* last decoded buffer was already dequeued. Set for capture queues
* when a buffer with the V4L2_BUF_FLAG_LAST is dequeued.
* @fileio: file io emulator internal data, used only if emulator is active
* @threadio: thread io internal data, used only if thread is active
*/
struct vb2_queue {
unsigned int type;
unsigned int io_modes;
struct device *dev;
unsigned long dma_attrs;
unsigned bidirectional:1;
unsigned fileio_read_once:1;
unsigned fileio_write_immediately:1;
unsigned allow_zero_bytesused:1;
unsigned quirk_poll_must_check_waiting_for_buffers:1;
struct mutex *lock;
void *owner;
const struct vb2_ops *ops;
const struct vb2_mem_ops *mem_ops;
const struct vb2_buf_ops *buf_ops;
void *drv_priv;
unsigned int buf_struct_size;
u32 timestamp_flags;
gfp_t gfp_flags;
u32 min_buffers_needed;
/* private: internal use only */
struct mutex mmap_lock;
unsigned int memory;
enum dma_data_direction dma_dir;
struct vb2_buffer *bufs[VB2_MAX_FRAME];
unsigned int num_buffers;
struct list_head queued_list;
unsigned int queued_count;
atomic_t owned_by_drv_count;
struct list_head done_list;
spinlock_t done_lock;
wait_queue_head_t done_wq;
struct device *alloc_devs[VB2_MAX_PLANES];
unsigned int streaming:1;
unsigned int start_streaming_called:1;
unsigned int error:1;
unsigned int waiting_for_buffers:1;
unsigned int is_multiplanar:1;
unsigned int is_output:1;
unsigned int copy_timestamp:1;
unsigned int last_buffer_dequeued:1;
struct vb2_fileio_data *fileio;
struct vb2_threadio_data *threadio;
#ifdef CONFIG_VIDEO_ADV_DEBUG
/*
* Counters for how often these queue-related ops are
* called. Used to check for unbalanced ops.
*/
u32 cnt_queue_setup;
u32 cnt_wait_prepare;
u32 cnt_wait_finish;
u32 cnt_start_streaming;
u32 cnt_stop_streaming;
#endif
};