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Commit 34f3c89f authored by Takashi Iwai's avatar Takashi Iwai
Browse files

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: default avatarMatthieu CASTET <matthieu.castet@parrot.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 978520b7

sound/usb/card.c

+8 −4
Original line number Diff line number Diff line
@@ -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(&register_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(&register_mutex);

		snd_card_free_when_closed(card);

	} else {

		mutex_unlock(&chip->shutdown_mutex);

		up_write(&chip->shutdown_rwsem);

		mutex_unlock(&register_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)

sound/usb/mixer.c

+6 −6
Original line number Diff line number Diff line
@@ -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;

}

sound/usb/pcm.c

+6 −6
Original line number Diff line number Diff line
@@ -503,12 +503,12 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream, 
		return -EINVAL;

	}



	mutex_lock(&subs->stream->chip->shutdown_mutex);

	down_read(&subs->stream->chip->shutdown_rwsem);

	if (subs->stream->chip->shutdown)

		ret = -ENODEV;

	else

		ret = set_format(subs, fmt);

	mutex_unlock(&subs->stream->chip->shutdown_mutex);

	up_read(&subs->stream->chip->shutdown_rwsem);

	if (ret < 0)

		return ret;
@@ -531,12 +531,12 @@ 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);

	if (!subs->stream->chip->shutdown) {

		stop_endpoints(subs, 0, 1, 1);

		deactivate_endpoints(subs);

	}

	mutex_unlock(&subs->stream->chip->shutdown_mutex);

	up_read(&subs->stream->chip->shutdown_rwsem);

	return snd_pcm_lib_free_vmalloc_buffer(substream);

}
@@ -558,7 +558,7 @@ 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;
@@ -608,7 +608,7 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream) 
		ret = start_endpoints(subs, 1);



 unlock:

	mutex_unlock(&subs->stream->chip->shutdown_mutex);

	up_read(&subs->stream->chip->shutdown_rwsem);

	return ret;

}

sound/usb/usbaudio.h

+1 −1
Original line number Diff line number Diff line
@@ -37,7 +37,7 @@ struct snd_usb_audio { 
	struct usb_interface *pm_intf;

	u32 usb_id;

	struct mutex mutex;

	struct mutex shutdown_mutex;

	struct rw_semaphore shutdown_rwsem;

	unsigned int shutdown:1;

	unsigned int probing:1;

	unsigned int autosuspended:1;