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authorTakashi Iwai <tiwai@suse.de>2012-11-07 12:42:45 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-11-17 13:16:12 -0800
commit49e44e317fdb73d75a00a058df75a6b6fe172c08 (patch)
treeabeaf4b344a9f59e76fce60b7d129d7fa6a36582 /sound
parent799c92f2aecb348e4a4c6dab80c7206e48caf201 (diff)
ALSA: usb-audio: Use rwsem for disconnect protection
commit 34f3c89fda4fba9fe689db22253ca8db2f5e6386 upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound')
-rw-r--r--sound/usb/card.c12
-rw-r--r--sound/usb/mixer.c12
-rw-r--r--sound/usb/pcm.c12
-rw-r--r--sound/usb/usbaudio.h2
4 files changed, 21 insertions, 17 deletions
diff --git a/sound/usb/card.c b/sound/usb/card.c
index 4a7be7b98331..147a5c42b95d 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -336,7 +336,7 @@ static int snd_usb_audio_create(struct usb_device *dev, int idx,
return -ENOMEM;
}
- mutex_init(&chip->shutdown_mutex);
+ init_rwsem(&chip->shutdown_rwsem);
chip->index = idx;
chip->dev = dev;
chip->card = card;
@@ -556,7 +556,7 @@ static void snd_usb_audio_disconnect(struct usb_device *dev,
card = chip->card;
mutex_lock(&register_mutex);
- mutex_lock(&chip->shutdown_mutex);
+ down_write(&chip->shutdown_rwsem);
chip->shutdown = 1;
chip->num_interfaces--;
if (chip->num_interfaces <= 0) {
@@ -574,11 +574,11 @@ 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(&register_mutex);
snd_card_free_when_closed(card);
} else {
- mutex_unlock(&chip->shutdown_mutex);
+ up_write(&chip->shutdown_rwsem);
mutex_unlock(&register_mutex);
}
}
@@ -610,16 +610,20 @@ 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)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index b3b63f769916..29ae209344d4 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -292,7 +292,7 @@ static int get_ctl_value_v1(struct usb_mixer_elem_info *cval, int request, int v
err = snd_usb_autoresume(cval->mixer->chip);
if (err < 0)
return -EIO;
- mutex_lock(&chip->shutdown_mutex);
+ down_read(&chip->shutdown_rwsem);
while (timeout-- > 0) {
if (chip->shutdown)
break;
@@ -310,7 +310,7 @@ static int get_ctl_value_v1(struct usb_mixer_elem_info *cval, int request, int v
err = -EINVAL;
out:
- mutex_unlock(&chip->shutdown_mutex);
+ up_read(&chip->shutdown_rwsem);
snd_usb_autosuspend(cval->mixer->chip);
return err;
}
@@ -337,7 +337,7 @@ static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request, int v
if (ret)
goto error;
- mutex_lock(&chip->shutdown_mutex);
+ down_read(&chip->shutdown_rwsem);
if (chip->shutdown)
ret = -ENODEV;
else {
@@ -346,7 +346,7 @@ static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request, int v
USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
validx, idx, buf, size);
}
- mutex_unlock(&chip->shutdown_mutex);
+ up_read(&chip->shutdown_rwsem);
snd_usb_autosuspend(chip);
if (ret < 0) {
@@ -453,7 +453,7 @@ int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
err = snd_usb_autoresume(chip);
if (err < 0)
return -EIO;
- mutex_lock(&chip->shutdown_mutex);
+ down_read(&chip->shutdown_rwsem);
while (timeout-- > 0) {
if (chip->shutdown)
break;
@@ -471,7 +471,7 @@ int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
err = -EINVAL;
out:
- mutex_unlock(&chip->shutdown_mutex);
+ up_read(&chip->shutdown_rwsem);
snd_usb_autosuspend(chip);
return err;
}
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 4f49ca75d6f1..4a99f6ca4b66 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -376,7 +376,7 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
subs->period_bytes != params_period_bytes(hw_params) ||
subs->cur_rate != rate;
- mutex_lock(&subs->stream->chip->shutdown_mutex);
+ down_read(&subs->stream->chip->shutdown_rwsem);
if (subs->stream->chip->shutdown) {
ret = -ENODEV;
goto unlock;
@@ -406,7 +406,7 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
}
unlock:
- mutex_unlock(&subs->stream->chip->shutdown_mutex);
+ up_read(&subs->stream->chip->shutdown_rwsem);
return ret;
}
@@ -422,9 +422,9 @@ static int snd_usb_hw_free(struct snd_pcm_substream *substream)
subs->cur_audiofmt = NULL;
subs->cur_rate = 0;
subs->period_bytes = 0;
- mutex_lock(&subs->stream->chip->shutdown_mutex);
+ down_read(&subs->stream->chip->shutdown_rwsem);
snd_usb_release_substream_urbs(subs, 0);
- mutex_unlock(&subs->stream->chip->shutdown_mutex);
+ up_read(&subs->stream->chip->shutdown_rwsem);
return snd_pcm_lib_free_vmalloc_buffer(substream);
}
@@ -444,7 +444,7 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
return -ENXIO;
}
- mutex_lock(&subs->stream->chip->shutdown_mutex);
+ down_read(&subs->stream->chip->shutdown_rwsem);
if (subs->stream->chip->shutdown) {
ret = -ENODEV;
goto unlock;
@@ -463,7 +463,7 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
ret = snd_usb_substream_prepare(subs, runtime);
unlock:
- mutex_unlock(&subs->stream->chip->shutdown_mutex);
+ up_read(&subs->stream->chip->shutdown_rwsem);
return ret;
}
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index 3e2b03577936..6c805a51d7d7 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -36,7 +36,7 @@ struct snd_usb_audio {
struct snd_card *card;
struct usb_interface *pm_intf;
u32 usb_id;
- struct mutex shutdown_mutex;
+ struct rw_semaphore shutdown_rwsem;
unsigned int shutdown:1;
unsigned int probing:1;
unsigned int autosuspended:1;