ALSA: firewire-motu: fix double unlocked 'motu->mutex'

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@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@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@sakamocchi.jp>
Link: https://lore.kernel.org/r/20191208232226.6685-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/firewire/motu/motu-pcm.c b/sound/firewire/motu/motu-pcm.c
index 349b4d09e84f6f885dd3a9bff2b0e29b127795e8..0059709310303c07a11bce1c04a551ac6502cdce 100644 (file)
--- 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;
-                       }
                }
        }