tree 073bc033c61a4045811e142dd30dea0e938d5568
parent 86266c58a7b0ac1929bc6080181343d54c4c13d8
author Alexandre Courbot <gnurou@gmail.com> 1598532585 +0200
committer Lecopzer Chen <lecopzer.chen@mediatek.com> 1628762907 +0000

UPSTREAM: media: v4l2-mem2mem: always consider OUTPUT queue during poll

If poll() is called on a m2m device with the EPOLLOUT event after the
last buffer of the CAPTURE queue is dequeued, any buffer available on
OUTPUT queue will never be signaled because v4l2_m2m_poll_for_data()
starts by checking whether dst_q->last_buffer_dequeued is set and
returns EPOLLIN in this case, without looking at the state of the OUTPUT
queue.

Fix this by not early returning so we keep checking the state of the
OUTPUT queue afterwards.

Bug: 196334249
(cherry picked from commit 566463afdbc43c7744c5a1b89250fc808df03833)
Signed-off-by: Alexandre Courbot <gnurou@gmail.com>
Reviewed-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Change-Id: I56d516211447a13e16c54b0b31b2ec397fe6e0da