Maxim Mikityanskiy c29dcb253a media: usbtv: Fix deadlock on suspend ...

commit 8a7e27fd5c upstream.

usbtv doesn't support power management, so on system suspend the
.disconnect callback of the driver is called. The teardown sequence
includes a call to snd_card_free. Its implementation waits until the
refcount of the sound card device drops to zero, however, if its file is
open, snd_card_file_add takes a reference, which can't be dropped during
the suspend, because the userspace processes are already frozen at this
point. snd_card_free waits for completion forever, leading to a hang on
suspend.

This commit fixes this deadlock condition by replacing snd_card_free
with snd_card_free_when_closed, that doesn't wait until all references
are released, allowing suspend to progress.

Fixes: 63ddf68de5 ("[media] usbtv: add audio support")
Signed-off-by: Maxim Mikityanskiy <maxtram95@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2021-03-17 17:06:20 +01:00

..

Kconfig

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Makefile

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usbtv-audio.c

media: usbtv: Fix deadlock on suspend

2021-03-17 17:06:20 +01:00

usbtv-core.c

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usbtv-video.c

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usbtv.h

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