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| author | Philipp Zabel <p.zabel@pengutronix.de> | 2015-05-04 07:51:06 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2015-05-12 03:53:06 -0300 |
| commit | c16218402a000bb25c1277c43ae98c11bcb59bd1 (patch) | |
| tree | cccdee965d974306a2ad6e67aeb0cc0ae356bc40 /drivers/media/v4l2-core/v4l2-mem2mem.c | |
| parent | dc199241624a2fd85d9b0d8303babd60feadd0e6 (diff) | |
| download | lwn-c16218402a000bb25c1277c43ae98c11bcb59bd1.tar.gz lwn-c16218402a000bb25c1277c43ae98c11bcb59bd1.zip | |
[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 'drivers/media/v4l2-core/v4l2-mem2mem.c')
| -rw-r--r-- | drivers/media/v4l2-core/v4l2-mem2mem.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c index 73824a5ada83..cbef15c07e53 100644 --- a/drivers/media/v4l2-core/v4l2-mem2mem.c +++ b/drivers/media/v4l2-core/v4l2-mem2mem.c @@ -564,8 +564,16 @@ unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, if (list_empty(&src_q->done_list)) poll_wait(file, &src_q->done_wq, wait); - if (list_empty(&dst_q->done_list)) + if (list_empty(&dst_q->done_list)) { + /* + * If the last buffer was dequeued from the capture queue, + * return immediately. DQBUF will return -EPIPE. + */ + if (dst_q->last_buffer_dequeued) + return rc | POLLIN | POLLRDNORM; + poll_wait(file, &dst_q->done_wq, wait); + } if (m2m_ctx->m2m_dev->m2m_ops->lock) m2m_ctx->m2m_dev->m2m_ops->lock(m2m_ctx->priv); |