[PATCH v2 1/2] drm: zynqmp_dp: Fix a deadlock in zynqmp_dp_ignore_hpd_set()

[Laurent Pinchart]

Hi Sean, Bart,

Thank you for the patch.

On Fri, Feb 07, 2025 at 11:25:27AM -0500, Sean Anderson wrote:
> From: Bart Van Assche <bvanassche at acm.org>
> 
> 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 at linux.dev>
> Cc: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
> Fixes: 28edaacb821c ("drm: zynqmp_dp: Add debugfs interface for compliance testing")
> Signed-off-by: Bart Van Assche <bvanassche at acm.org>
> Reviewed-by: Sean Anderson <sean.anderson at linux.dev>
> Signed-off-by: Sean Anderson <sean.anderson at linux.dev>

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> ---
> 
> (no changes since v1)
> 
>  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;
>  }
>  

-- 
Regards,

Laurent Pinchart