Re: [Intel-gfx] [PATCH 1/5] drm/i915/dp: Add helper to check DSC1.2 for HDMI2.1 DFP

[Jani Nikula <jani.nikula@linux.intel.com>]

On Mon, 22 Aug 2022, Ankit Nautiyal <ankit.k.nautiyal@intel.com> wrote:
> Add helper function to check if Downstream HDMI 2.1 sink supports
> DSC1.2.

If we do this, are we going to add helpers for all the details in
display_info, when there's no conversions being done? I think the answer
should be "no".

i.e. why do we really need this?

BR,
Jani.

>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 32292c0be2bd..fdf82373a22d 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -118,6 +118,15 @@ bool intel_dp_is_edp(struct intel_dp *intel_dp)
>  static void intel_dp_unset_edid(struct intel_dp *intel_dp);
>  static int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 dsc_max_bpc);
>  
> +static bool
> +is_dfp_hdmi_sink_dsc_1_2(struct intel_dp *intel_dp)
> +{
> +	struct intel_connector *intel_connector = intel_dp->attached_connector;
> +	struct drm_connector *connector = &intel_connector->base;
> +
> +	return connector->display_info.hdmi.dsc_cap.v_1p2;
> +}
> +
>  /* Is link rate UHBR and thus 128b/132b? */
>  bool intel_dp_is_uhbr(const struct intel_crtc_state *crtc_state)
>  {
> @@ -2393,7 +2402,7 @@ static int intel_dp_hdmi_sink_max_frl(struct intel_dp *intel_dp)
>  	rate_per_lane = connector->display_info.hdmi.max_frl_rate_per_lane;
>  	max_frl_rate = max_lanes * rate_per_lane;
>  
> -	if (connector->display_info.hdmi.dsc_cap.v_1p2) {
> +	if (is_dfp_hdmi_sink_dsc_1_2(intel_dp)) {
>  		max_dsc_lanes = connector->display_info.hdmi.dsc_cap.max_lanes;
>  		dsc_rate_per_lane = connector->display_info.hdmi.dsc_cap.max_frl_rate_per_lane;
>  		if (max_dsc_lanes && dsc_rate_per_lane)
> @@ -2605,7 +2614,7 @@ intel_dp_pcon_dsc_configure(struct intel_dp *intel_dp,
>  	if (!intel_connector)
>  		return;
>  	connector = &intel_connector->base;
> -	hdmi_is_dsc_1_2 = connector->display_info.hdmi.dsc_cap.v_1p2;
> +	hdmi_is_dsc_1_2 = is_dfp_hdmi_sink_dsc_1_2(intel_dp);
>  
>  	if (!drm_dp_pcon_enc_is_dsc_1_2(intel_dp->pcon_dsc_dpcd) ||
>  	    !hdmi_is_dsc_1_2)

-- 
Jani Nikula, Intel Open Source Graphics Center