[alsa-devel] [PATCH] firewire-motu: fix double unlocked 'motu->mutex'

[Takashi Sakamoto]

Mutex is doubly unlocked in some error path of pcm.open. This commit fixes
ALSA firewire-motu driver in Linux kernel v5.5.

Reported-by: kbuild test robot <lkp at intel.com>
Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
Fixes: 3fd80b200388 ("ALSA: firewire-motu: use the same size of period for PCM substream in AMDTP streams")
Fixes: 0f5482e7875b ("ALSA: firewire-motu: share PCM buffer size for both direction")
Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
 sound/firewire/motu/motu-pcm.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/sound/firewire/motu/motu-pcm.c b/sound/firewire/motu/motu-pcm.c
index 349b4d09e84f..005970931030 100644
--- a/sound/firewire/motu/motu-pcm.c
+++ b/sound/firewire/motu/motu-pcm.c
@@ -177,18 +177,14 @@ static int pcm_open(struct snd_pcm_substream *substream)
 			err = snd_pcm_hw_constraint_minmax(substream->runtime,
 					SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
 					frames_per_period, frames_per_period);
-			if (err < 0) {
-				mutex_unlock(&motu->mutex);
+			if (err < 0)
 				goto err_locked;
-			}
 
 			err = snd_pcm_hw_constraint_minmax(substream->runtime,
 					SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
 					frames_per_buffer, frames_per_buffer);
-			if (err < 0) {
-				mutex_unlock(&motu->mutex);
+			if (err < 0)
 				goto err_locked;
-			}
 		}
 	}
 
-- 
2.20.1