Re: [PATCH 2/2] drm/i915/dp_mst: Fix ww mutex lock failure in for_each_joiner_candidate() loop

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 2/18/2026 4:27 PM, Imre Deak wrote:
> Handle modeset WW mutex lock failures due to contention properly.
> Return -EDEADLK to the caller instead of attempting to lock the same
> mutex again in a subsequent joiner candidate iteration, where the WW
> mutex is already in a contended state.
>
> This fixes the following warning:
>
> WARNING: drivers/gpu/drm/drm_modeset_lock.c:298 at modeset_lock+0x1c0/0x210
>
> triggered by ctx->contended.
>
> Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> Fixes: b506a8e18c972 ("drm/i915/dp_mst: Rework pipe joiner logic in compute_config")
> Signed-off-by: Imre Deak <imre.deak@intel.com>

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>


> ---
>   drivers/gpu/drm/i915/display/intel_dp_mst.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index f833f47643271..94c0231426642 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -729,7 +729,7 @@ static int mst_stream_compute_config(struct intel_encoder *encoder,
>   							       pipe_config,
>   							       conn_state,
>   							       num_joined_pipes);
> -		if (ret == 0)
> +		if (ret == 0 || ret == -EDEADLK)
>   			break;
>   	}
>