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

[Takashi Sakamoto]

Oops. I forgot to add 'ALSA: ' prefix to the subject line. I'm sorry but would I
request maintainers to add it when applying...

On Mon, Dec 9, 2019, at 08:22, Takashi Sakamoto wrote:
> 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
> 
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