path: root/include/media/videobuf2-core.h
diff options
authorPhilipp Zabel <p.zabel@pengutronix.de>2015-05-04 07:51:06 -0300
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>2015-05-12 03:53:06 -0300
commitc16218402a000bb25c1277c43ae98c11bcb59bd1 (patch)
treecccdee965d974306a2ad6e67aeb0cc0ae356bc40 /include/media/videobuf2-core.h
parentdc199241624a2fd85d9b0d8303babd60feadd0e6 (diff)
[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 <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>
Diffstat (limited to 'include/media/videobuf2-core.h')
1 files changed, 13 insertions, 0 deletions
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,

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