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media: v4l2-mem2mem: prevent pollerr when last_buffer_dequeued is set

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[ Upstream commit d4de27a9b1eadd33a2e40de87a646d1bf5fef756 ]

If the last buffer was dequeued from the capture queue,
signal userspace. DQBUF(CAPTURE) will return -EPIPE.

But if output queue is empty and capture queue is empty,
v4l2_m2m_poll_for_data will return EPOLLERR,
This is very easy to happen in drain.

When last_buffer_dequeued is set, we shouldn't return EPOLLERR,
but return EPOLLIN | EPOLLRDNORM.

Fixes: 1698a7f151126 ("media: v4l2-mem2mem: simplify poll logic")
Signed-off-by: Ming Qian <ming.qian@nxp.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Ming Qian 2022-06-15 04:19:20 +01:00 committed by Greg Kroah-Hartman
parent bb480bffc1
commit 7f7336ce35
1 changed files with 1 additions and 1 deletions
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2
drivers/media/v4l2-core/v4l2-mem2mem.c
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@ -927,7 +927,7 @@ static __poll_t v4l2_m2m_poll_for_data(struct file *file,
if ((!src_q->streaming || src_q->error ||
list_empty(&src_q->queued_list)) &&
(!dst_q->streaming || dst_q->error ||
list_empty(&dst_q->queued_list)))
(list_empty(&dst_q->queued_list) && !dst_q->last_buffer_dequeued)))
return EPOLLERR;
spin_lock_irqsave(&src_q->done_lock, flags);