linux/sound/usb
Takashi Iwai 10e44239f6 ALSA: usb-audio: Fix mutex deadlock at disconnection
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>
2012-11-14 15:29:09 +01:00
..
6fire ALSA: print small buffers via %*ph[C] 2012-08-06 11:09:50 +02:00
caiaq ALSA: snd-usb-caiaq: initialize card pointer 2012-06-27 12:26:19 +02:00
misc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound 2012-01-12 08:00:30 -08:00
usx2y mm: kill vma flag VM_RESERVED and mm->reserved_vm counter 2012-10-09 16:22:19 +09:00
Kconfig ALSA: snd-usb-6fire: Select missing SND_VMASTER option in Kconfig 2012-02-25 11:07:19 +01:00
Makefile ALSA: snd-usb: move code from urb.c to endpoint.c 2011-09-14 17:07:03 +02:00
card.c ALSA: usb-audio: Fix mutex deadlock at disconnection 2012-11-14 15:29:09 +01:00
card.h ALSA: usb-audio: Fix races at disconnection 2012-10-30 11:06:54 +01:00
clock.c ALSA: snd-usb: fix clock source validity index 2012-08-01 10:24:16 +02:00
clock.h ALSA: usb-audio: simplify control interface access 2010-06-23 16:10:23 +02:00
debug.h ALSA: usb-audio: make hwc_debug a noop in case HW_CONST_DEBUG is not set 2011-05-18 11:44:35 +02:00
endpoint.c ALSA: usb-audio: Fix crash at re-preparing the PCM stream 2012-11-08 08:56:44 +01:00
endpoint.h ALSA: usb-audio: Fix crash at re-preparing the PCM stream 2012-11-08 08:56:44 +01:00
format.c ALSA: usb-audio: avoid integer overflow in create_fixed_stream_quirk() 2012-02-15 14:58:15 +01:00
format.h ALSA: usb-audio: parse more format descriptors with structs 2010-05-27 09:48:31 +02:00
helper.c ALSA: snd-usb: Add quirks for Playback Designs devices 2012-09-04 11:31:14 +02:00
helper.h ALSA: usb-audio: increase control transfer timeout 2011-09-27 09:21:48 +02:00
midi.c sound: Add module.h to the previously silent sound users 2011-10-31 19:31:21 -04:00
midi.h ALSA: usb-audio: add support for Akai MPD16 2010-05-21 17:12:30 +02:00
mixer.c ALSA: usb-audio: Use rwsem for disconnect protection 2012-10-30 11:07:00 +01:00
mixer.h ALSA: usb-audio: Rename and export mixer_vol_tlv 2012-04-24 08:01:27 +02:00
mixer_maps.c ALSA: snd_usb_audio: ignore ctrl errors on QuickCam Pro for Notebooks 2012-06-20 08:29:08 +02:00
mixer_quirks.c ALSA: usb-audio: Fix races at disconnection in mixer_quirks.c 2012-10-30 11:07:05 +01:00
mixer_quirks.h ALSA: usb-mixer: factor out quirks 2010-03-12 12:20:26 +01:00
pcm.c ALSA: usb-audio: Fix crash at re-preparing the PCM stream 2012-11-08 08:56:44 +01:00
pcm.h ALSA: usb: refine delay information with USB frame counter 2011-09-12 10:30:20 +02:00
power.h ALSA: usbaudio: implement USB autosuspend 2011-03-11 14:59:29 +01:00
proc.c ALSA: usb-audio: Fix races at disconnection 2012-10-30 11:06:54 +01:00
proc.h ALSA: usb-audio: refactor code 2010-03-05 08:17:14 +01:00
quirks-table.h ALSA: usb-audio: Add TASCAM US122 MKII playback 2012-10-08 15:16:33 +02:00
quirks.c ALSA: snd-usb: Add quirks for Playback Designs devices 2012-09-04 11:31:14 +02:00
quirks.h ALSA: snd-usb: Add quirks for Playback Designs devices 2012-09-04 11:31:14 +02:00
stream.c ALSA: usb-audio: Fix races at disconnection 2012-10-30 11:06:54 +01:00
stream.h ALSA: snd-usb: re-order code 2011-09-14 17:07:02 +02:00
usbaudio.h ALSA: usb-audio: Use rwsem for disconnect protection 2012-10-30 11:07:00 +01:00