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*参照元 [#m1190ca3] #backlinks *説明 [#td28b60c] -パス: [[linux-4.4.1/include/media/videobuf2-core.h]] -FIXME: これは何？ --説明 **参考 [#se55206f] *実装 [#t0fabaf3] /** * 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 V4L2_BUF_TYPE_* in include/uapi/linux/videodev2.h * @io_modes: supported io methods (see vb2_io_modes enum) * @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 * @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 DocBook): * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped * @memory: current memory type used * @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_ctx: memory type/allocator-specific contexts for each plane * @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 * @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; unsigned fileio_read_once:1; unsigned fileio_write_immediately:1; unsigned allow_zero_bytesused:1; struct mutex *lock; void *owner; - --[[linux-4.4.1/mutex]] const struct vb2_ops *ops; const struct vb2_mem_ops *mem_ops; const struct vb2_buf_ops *buf_ops; - --[[linux-4.4.1/vb2_ops]] --[[linux-4.4.1/vb2_mem_ops]] --[[linux-4.4.1/vb2_buf_ops]] void *drv_priv; unsigned int buf_struct_size; u32 timestamp_flags; gfp_t gfp_flags; u32 min_buffers_needed; - --[[linux-4.4.1/gfp_t]] /* private: internal use only */ struct mutex mmap_lock; unsigned int memory; struct vb2_buffer *bufs[VB2_MAX_FRAME]; unsigned int num_buffers; - --[[linux-4.4.1/vb2_buffer]] struct list_head queued_list; unsigned int queued_count; - --[[linux-4.4.1/list_head]] atomic_t owned_by_drv_count; struct list_head done_list; spinlock_t done_lock; wait_queue_head_t done_wq; - --[[linux-4.4.1/atomic_t]] --[[linux-4.4.1/spinlock_t]] --[[linux-4.4.1/wait_queue_head_t]] void *alloc_ctx[VB2_MAX_PLANES]; unsigned int plane_sizes[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 last_buffer_dequeued:1; struct vb2_fileio_data *fileio; struct vb2_threadio_data *threadio; - --[[linux-4.4.1/vb2_fileio_data]] --[[linux-4.4.1/vb2_threadio_data]] #ifdef CONFIG_VIDEO_ADV_DEBUG - --[[linux-4.4.1/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 }; *コメント [#qba40a5a]
