media: cec: avoid decrementing transmit_queue_sz if it is 0
authorHans Verkuil <hverkuil-cisco@xs4all.nl>
Sat, 7 Dec 2019 22:48:09 +0000 (23:48 +0100)
committerMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Fri, 13 Dec 2019 10:22:10 +0000 (11:22 +0100)
commit95c29d46ab2a517e4c26d0a07300edca6768db17
tree5ede0da3b7a4d38a76b75f15880e5e21432a904a
parentcec935ce69fc386f13959578deb40963ebbb85c3
media: cec: avoid decrementing transmit_queue_sz if it is 0

WARN if transmit_queue_sz is 0 but do not decrement it.
The CEC adapter will become unresponsive if it goes below
0 since then it thinks there are 4 billion messages in the
queue.

Obviously this should not happen, but a driver bug could
cause this.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: <stable@vger.kernel.org> # for v4.12 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
drivers/media/cec/cec-adap.c