Instead of attempting the same mutex twice, lock and unlock it.

This bug has been detected by the Clang thread-safety analyzer.

Cc: Sean Anderson <sean.anderson@linux.dev>
Cc: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Fixes: 28edaacb821c ("drm: zynqmp_dp: Add debugfs interface for compliance testing")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/gpu/drm/xlnx/zynqmp_dp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
index 979f6d3239ba..189a08cdc73c 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
@@ -2295,7 +2295,7 @@ static int zynqmp_dp_ignore_hpd_set(void *data, u64 val)
 
 	mutex_lock(&dp->lock);
 	dp->ignore_hpd = val;
-	mutex_lock(&dp->lock);
+	mutex_unlock(&dp->lock);
 	return 0;
 }
 

On 2/6/25 12:51, Bart Van Assche wrote:
> Instead of attempting the same mutex twice, lock and unlock it.
> 
> This bug has been detected by the Clang thread-safety analyzer.
> 
> Cc: Sean Anderson <sean.anderson@linux.dev>
> Cc: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> Fixes: 28edaacb821c ("drm: zynqmp_dp: Add debugfs interface for compliance testing")
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
>  drivers/gpu/drm/xlnx/zynqmp_dp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
> index 979f6d3239ba..189a08cdc73c 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
> +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
> @@ -2295,7 +2295,7 @@ static int zynqmp_dp_ignore_hpd_set(void *data, u64 val)
>  
>  	mutex_lock(&dp->lock);
>  	dp->ignore_hpd = val;
> -	mutex_lock(&dp->lock);
> +	mutex_unlock(&dp->lock);
>  	return 0;
>  }
>  

Reviewed-by: Sean Anderson <sean.anderson@seco.com>

Since this patch is marked RFC will it be applied soon? I am about to
send a patch which conflicts with this one. I would like to just add
this patch to my series.

--Sean

On 2/6/25 11:22 AM, Sean Anderson wrote:
> Since this patch is marked RFC will it be applied soon? I am about to
> send a patch which conflicts with this one. I would like to just add
> this patch to my series.

Hi Sean,

Thanks for having taken a look. Please include this patch in your patch
series if you want it to be merged in the upstream kernel soon.

Bart.