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>
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index c2ef11c..298070e 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -292,7 +292,7 @@
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 @@
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 @@
if (ret)
goto error;
- mutex_lock(&chip->shutdown_mutex);
+ down_read(&chip->shutdown_rwsem);
if (chip->shutdown)
ret = -ENODEV;
else {
@@ -346,7 +346,7 @@
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 @@
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 @@
err = -EINVAL;
out:
- mutex_unlock(&chip->shutdown_mutex);
+ up_read(&chip->shutdown_rwsem);
snd_usb_autosuspend(chip);
return err;
}