From 34f3c89fda4fba9fe689db22253ca8db2f5e6386 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 15 Oct 2012 12:16:02 +0200 Subject: 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 Cc: Signed-off-by: Takashi Iwai --- sound/usb/card.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'sound/usb/card.c') 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) -- cgit v1.2.3