From c16218402a000bb25c1277c43ae98c11bcb59bd1 Mon Sep 17 00:00:00 2001 From: Philipp Zabel Date: Mon, 4 May 2015 07:51:06 -0300 Subject: [media] videobuf2: return -EPIPE from DQBUF after the last buffer If the last buffer was dequeued from a capture queue, let poll return immediately and let DQBUF return -EPIPE to signal there will no more buffers to dequeue until STREAMOFF. The driver signals the last buffer by setting the V4L2_BUF_FLAG_LAST. To reenable dequeuing on the capture queue, the driver must explicitly call vb2_clear_last_buffer_queued. The last buffer queued flag is cleared automatically during STREAMOFF. Signed-off-by: Philipp Zabel Acked-by: Hans Verkuil Signed-off-by: Kamil Debski Signed-off-by: Mauro Carvalho Chehab --- include/media/videobuf2-core.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include/media/videobuf2-core.h') diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index a5790fd5d125..22a44c2f5963 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -381,6 +381,9 @@ struct v4l2_fh; * @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. + * @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 */ @@ -423,6 +426,7 @@ struct vb2_queue { unsigned int start_streaming_called:1; unsigned int error:1; unsigned int waiting_for_buffers:1; + unsigned int last_buffer_dequeued:1; struct vb2_fileio_data *fileio; struct vb2_threadio_data *threadio; @@ -603,6 +607,15 @@ static inline bool vb2_start_streaming_called(struct vb2_queue *q) return q->start_streaming_called; } +/** + * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue + * @q: videobuf queue + */ +static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q) +{ + q->last_buffer_dequeued = false; +} + /* * The following functions are not part of the vb2 core API, but are simple * helper functions that you can use in your struct v4l2_file_operations, -- cgit v1.2.3