Re: [PATCH 2/2] drm/i915/dp: Restore the missing check for intel_dp_has_joiner

[Imre Deak <imre.deak@intel.com>]

On Fri, Feb 06, 2026 at 10:17:53AM +0530, Ankit Nautiyal wrote:
> Commit ad121a62d566 ("drm/i915/dp: Rework pipe joiner logic in mode_valid")
> replaced intel_dp_num_joined_pipes() with an explicit joiner candidate
> iteration. The previous code implicitly checked for DP joiner capability
> via intel_dp_has_joiner(), but this check was lost during the refactor.
> 
> Restore the missing intel_dp_has_joiner() check in intel_dp_can_join() so
> that DP specific joiner conditions are taken into account.
> 
> v2: Derive intel_dp from intel_attached_dp(). (Imre)
> 
> Fixes: ad121a62d566 ("drm/i915/dp: Rework pipe joiner logic in mode_valid")
> Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> Cc: Imre Deak <imre.deak@intel.com>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>

Reviewed-by: Imre Deak <imre.deak@intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 4f5b89f80e55..7da4310b399e 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -1397,9 +1397,14 @@ bool intel_dp_has_dsc(const struct intel_connector *connector)
>  }
>  
>  static
> -bool intel_dp_can_join(struct intel_display *display,
> +bool intel_dp_can_join(struct intel_dp *intel_dp,
>  		       int num_joined_pipes)
>  {
> +	struct intel_display *display = to_intel_display(intel_dp);
> +
> +	if (num_joined_pipes > 1 && !intel_dp_has_joiner(intel_dp))
> +		return false;
> +
>  	switch (num_joined_pipes) {
>  	case 1:
>  		return true;
> @@ -7218,8 +7223,9 @@ bool intel_dp_joiner_candidate_valid(struct intel_connector *connector,
>  				     int num_joined_pipes)
>  {
>  	struct intel_display *display = to_intel_display(connector);
> +	struct intel_dp *intel_dp = intel_attached_dp(connector);
>  
> -	if (!intel_dp_can_join(display, num_joined_pipes))
> +	if (!intel_dp_can_join(intel_dp, num_joined_pipes))
>  		return false;
>  
>  	if (hdisplay > num_joined_pipes * intel_dp_max_hdisplay_per_pipe(display))
> -- 
> 2.45.2
>