diff options
| author | Takashi Iwai <tiwai@suse.de> | 2012-10-15 12:16:02 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2012-10-30 11:07:00 +0100 |
| commit | 34f3c89fda4fba9fe689db22253ca8db2f5e6386 (patch) | |
| tree | 213e1b6e6ceaee42dc4f9ec74307794dc7a83b20 /sound/usb/card.c | |
| parent | ALSA: usb-audio: Fix races at disconnection (diff) | |
| download | linux-34f3c89fda4fba9fe689db22253ca8db2f5e6386.tar.xz linux-34f3c89fda4fba9fe689db22253ca8db2f5e6386.zip | |
ALSA: usb-audio: Use rwsem for disconnect protection
Replace mutex with rwsem for codec->shutdown protection so that
concurrent accesses are allowed.
Also add the protection to snd_usb_autosuspend() and
snd_usb_autoresume(), too.
Reported-by: Matthieu CASTET <matthieu.castet@parrot.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/card.c')
| -rw-r--r-- | sound/usb/card.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/sound/usb/card.c b/sound/usb/card.c index 561bb74fd364..282f0fc9fed1 100644 --- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -339,7 +339,7 @@ static int snd_usb_audio_create(struct usb_device *dev, int idx, } mutex_init(&chip->mutex); - mutex_init(&chip->shutdown_mutex); + init_rwsem(&chip->shutdown_rwsem); chip->index = idx; chip->dev = dev; chip->card = card; @@ -560,7 +560,7 @@ static void snd_usb_audio_disconnect(struct usb_device *dev, card = chip->card; mutex_lock(®ister_mutex); - mutex_lock(&chip->shutdown_mutex); + down_write(&chip->shutdown_rwsem); chip->shutdown = 1; chip->num_interfaces--; if (chip->num_interfaces <= 0) { @@ -582,11 +582,11 @@ static void snd_usb_audio_disconnect(struct usb_device *dev, snd_usb_mixer_disconnect(p); } usb_chip[chip->index] = NULL; - mutex_unlock(&chip->shutdown_mutex); + up_write(&chip->shutdown_rwsem); mutex_unlock(®ister_mutex); snd_card_free_when_closed(card); } else { - mutex_unlock(&chip->shutdown_mutex); + up_write(&chip->shutdown_rwsem); mutex_unlock(®ister_mutex); } } @@ -618,16 +618,20 @@ int snd_usb_autoresume(struct snd_usb_audio *chip) { int err = -ENODEV; + down_read(&chip->shutdown_rwsem); if (!chip->shutdown && !chip->probing) err = usb_autopm_get_interface(chip->pm_intf); + up_read(&chip->shutdown_rwsem); return err; } void snd_usb_autosuspend(struct snd_usb_audio *chip) { + down_read(&chip->shutdown_rwsem); if (!chip->shutdown && !chip->probing) usb_autopm_put_interface(chip->pm_intf); + up_read(&chip->shutdown_rwsem); } static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message) |