Re: [PATCH RFC 24/33] drm: zynqmp_dp: Fix a deadlock in zynqmp_dp_ignore_hpd_set()

From: Sean Anderson
Date: Thu Feb 06 2025 - 14:23:18 EST


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@xxxxxxxxx>
> Cc: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
> Fixes: 28edaacb821c ("drm: zynqmp_dp: Add debugfs interface for compliance testing")
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
> 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@xxxxxxxx>

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