Re: [PATCH 6/9] drm/i915/dp: Require a HDMI sink for YCbCr output via PCON

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

On 3/31/2026 5:23 AM, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> DVI sinks can't deal with YCbCr. Make sure we have a HDMI sink connected
> after the PCON before doing YCbCr 4:2:0 output.
>
> Cc: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

LGTM.

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


> ---
>   drivers/gpu/drm/i915/display/intel_dp.c | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 86319bf09a19..ce40d38557e1 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -1358,10 +1358,15 @@ intel_dp_sink_format_valid(struct intel_connector *connector,
>   			   const struct drm_display_mode *mode,
>   			   enum intel_output_format sink_format)
>   {
> +	struct intel_dp *intel_dp = intel_attached_dp(connector);
>   	const struct drm_display_info *info = &connector->base.display_info;
>   
>   	switch (sink_format) {
>   	case INTEL_OUTPUT_FORMAT_YCBCR420:
> +		if (intel_dp->dfp.min_tmds_clock &&
> +		    !intel_dp_has_hdmi_sink(intel_dp))
> +			return MODE_NO_420;
> +
>   		if (!connector->base.ycbcr_420_allowed ||
>   		    !drm_mode_is_420(info, mode))
>   			return MODE_NO_420;