mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-07-16 14:30:06 -04:00
Code Issues Packages Projects Releases Wiki Activity

[media] videobuf2: return -EPIPE from DQBUF after the last buffer

Browse Source 
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 <p.zabel@pengutronix.de>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This commit is contained in:
Philipp Zabel
2015-05-04 07:51:06 -03:00
committed by Mauro Carvalho Chehab
parent dc19924162
commit c16218402a
3 changed files with 40 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
include/media/videobuf2-core.h
View File

@@ -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,