Re: [PATCH 03/14] drm/i915/dp: Add a helper to decide if AS SDP is needed

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Mon, Feb 23, 2026 at 07:14:20PM +0530, Ankit Nautiyal wrote:
> Add a helper to check if AS SDP is needed. Currently AS SDP is only
> required when VRR is enabled. However, there are other use cases, along
> with the missing case of CMRR, dealt in subsequent changes.
> 
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index b999d8c085c7..65764ab0bb9b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -3111,6 +3111,12 @@ static void intel_dp_compute_vsc_colorimetry(const struct intel_crtc_state *crtc
>  	vsc->content_type = DP_CONTENT_TYPE_NOT_DEFINED;
>  }
>  
> +static bool intel_dp_needs_as_sdp(struct intel_dp *intel_dp,
> +				  struct intel_crtc_state *crtc_state)
> +{
> +	return crtc_state->vrr.enable;

Since we don't support VRR+PCON I don't think we actually
need the AS SDP for VRR.

And I don't think we even have a fastset path for this stuff
(or where is it?) so isn't this already causing fastset
failures for VRR enable/disable? Or maybe we don't have
displays with both VRR and AS SDP support anywhere?

> +}
> +
>  static void intel_dp_compute_as_sdp(struct intel_dp *intel_dp,
>  				    struct intel_crtc_state *crtc_state)
>  {
> @@ -3118,7 +3124,10 @@ static void intel_dp_compute_as_sdp(struct intel_dp *intel_dp,
>  	const struct drm_display_mode *adjusted_mode =
>  		&crtc_state->hw.adjusted_mode;
>  
> -	if (!crtc_state->vrr.enable || !intel_dp->as_sdp_supported)
> +	if (!intel_dp->as_sdp_supported)
> +		return;
> +
> +	if (!intel_dp_needs_as_sdp(intel_dp, crtc_state))
>  		return;
>  
>  	crtc_state->infoframes.enable |= intel_hdmi_infoframe_enable(DP_SDP_ADAPTIVE_SYNC);
> -- 
> 2.45.2

-- 
Ville Syrjälä
Intel