forked from luck/tmp_suning_uos_patched
10e44239f6
The recent change for USB-audio disconnection race fixes introduced a
mutex deadlock again. There is a circular dependency between
chip->shutdown_rwsem and pcm->open_mutex, depicted like below, when a
device is opened during the disconnection operation:
A. snd_usb_audio_disconnect() ->
card.c::register_mutex ->
chip->shutdown_rwsem (write) ->
snd_card_disconnect() ->
pcm.c::register_mutex ->
pcm->open_mutex
B. snd_pcm_open() ->
pcm->open_mutex ->
snd_usb_pcm_open() ->
chip->shutdown_rwsem (read)
Since the chip->shutdown_rwsem protection in the case A is required
only for turning on the chip->shutdown flag and it doesn't have to be
taken for the whole operation, we can reduce its window in
snd_usb_audio_disconnect().
Reported-by: Jiri Slaby <jslaby@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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| .. | ||
| 6fire | ||
| caiaq | ||
| misc | ||
| usx2y | ||
| card.c | ||
| card.h | ||
| clock.c | ||
| clock.h | ||
| debug.h | ||
| endpoint.c | ||
| endpoint.h | ||
| format.c | ||
| format.h | ||
| helper.c | ||
| helper.h | ||
| Kconfig | ||
| Makefile | ||
| midi.c | ||
| midi.h | ||
| mixer_maps.c | ||
| mixer_quirks.c | ||
| mixer_quirks.h | ||
| mixer.c | ||
| mixer.h | ||
| pcm.c | ||
| pcm.h | ||
| power.h | ||
| proc.c | ||
| proc.h | ||
| quirks-table.h | ||
| quirks.c | ||
| quirks.h | ||
| stream.c | ||
| stream.h | ||
| usbaudio.h | ||