On 03/09/2018 09:49 AM, Gustavo Padovan wrote:
> From: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxx>
>
> Explicit synchronization benefits a lot from ordered queues, they fit
> better in a pipeline with DRM for example so create a opt-in way for
> drivers notify videobuf2 that the queue is unordered.
>
> Drivers don't need implement it if the queue is ordered.
>
> v2: - improve comments for is_unordered flag (Hans)
>
> v3: - make it bool (Hans)
> - create vb2_ops_set_unordered() helper
>
> Signed-off-by: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxx>
> ---
> drivers/media/common/videobuf2/videobuf2-v4l2.c | 6 ++++++
> include/media/videobuf2-core.h | 6 ++++++
> include/media/videobuf2-v4l2.h | 10 ++++++++++
> 3 files changed, 22 insertions(+)
>
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index 886a2d8d5c6c..68291ba8632d 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -961,6 +961,12 @@ void vb2_ops_wait_finish(struct vb2_queue *vq)
> }
> EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
>
> +bool vb2_ops_set_unordered(struct vb2_queue *q)
> +{
> + return true;
> +}
> +EXPORT_SYMBOL_GPL(vb2_ops_set_unordered);
This should be called vb2_ops_is_unordered. The name after the vb2_ops_
prefix should match the op name (is_unordered).
I also would add this to videobuf2-core.c since there is nothing V4L2
specific about this.
> +
> MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
> MODULE_AUTHOR("Pawel Osciak <pawel@xxxxxxxxxx>, Marek Szyprowski");
> MODULE_LICENSE("GPL");
> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
> index 5b6c541e4e1b..46a9e674f7e1 100644
> --- a/include/media/videobuf2-core.h
> +++ b/include/media/videobuf2-core.h
> @@ -370,6 +370,10 @@ struct vb2_buffer {
> * 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
> + * @is_unordered: tell if the queue is unordered, i.e. buffers can be
> + * dequeued in a different order from how they were queued.
> + * The default is assumed to be ordered and this function
> + * only needs to be implemented for unordered queues.
> * @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;
> @@ -393,6 +397,7 @@ struct vb2_ops {
>
> int (*start_streaming)(struct vb2_queue *q, unsigned int count);
> void (*stop_streaming)(struct vb2_queue *q);
> + bool (*is_unordered)(struct vb2_queue *q);
>
> void (*buf_queue)(struct vb2_buffer *vb);
> };
> @@ -566,6 +571,7 @@ struct vb2_queue {
> u32 cnt_wait_finish;
> u32 cnt_start_streaming;
> u32 cnt_stop_streaming;
> + u32 cnt_is_unordered;
> #endif
> };
>
> diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
> index 3d5e2d739f05..9de3c887c875 100644
> --- a/include/media/videobuf2-v4l2.h
> +++ b/include/media/videobuf2-v4l2.h
> @@ -291,4 +291,14 @@ void vb2_ops_wait_prepare(struct vb2_queue *vq);
> */
> void vb2_ops_wait_finish(struct vb2_queue *vq);
>
> +/**
> + * vb2_ops_set_unordered - helper function to mark queue as unordered
> + *
> + * @vq: pointer to &struct vb2_queue
> + *
> + * This helper just return true to notify that the driver can't deal with
return -> returns
> + * ordered queues.
> + */
> +bool vb2_ops_set_unordered(struct vb2_queue *q);
> +
> #endif /* _MEDIA_VIDEOBUF2_V4L2_H */
>
Regards,
Hans
