drm/i915: Add DSC/FEC support info to debugfs

[Imre Deak]

On Fri, Apr 04, 2025 at 12:34:48AM +0530, shantam.yashashvi at intel.com wrote:
> From: Shantam Yashashvi <shantam.yashashvi at intel.com>
> 
> Signed-off-by: Shantam Yashashvi <shantam.yashashvi at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display_debugfs.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> index 057a8ce0c2c97..b8d3a438a34d9 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> @@ -276,6 +276,7 @@ static void intel_connector_info(struct seq_file *m,
>  	struct intel_encoder *encoder =
>  		to_intel_encoder(conn_state->best_encoder);
>  	const struct drm_display_mode *mode;
> +	struct intel_dp *intel_dp;
>  
>  	seq_printf(m, "[CONNECTOR:%d:%s]: status: %s\n",
>  		   connector->base.id, connector->name,
> @@ -301,6 +302,16 @@ static void intel_connector_info(struct seq_file *m,
>  			intel_dp_mst_info(m, intel_connector);
>  		else
>  			intel_dp_info(m, intel_connector);
> +
> +		/* Add DSC and FEC Support Information for DisplayPort / eDP Connectors */
> +		intel_dp = intel_attached_dp(intel_connector);
> +		if (intel_dp){
> +			seq_printf(m, "\tDSC_Sink_Support: %s\n",
> +                str_yes_no(drm_dp_sink_supports_dsc(intel_connector->dp.dsc_dpcd)));
> +			if (!intel_dp_is_edp(intel_dp))
> +				    seq_printf(m, "\tFEC_Sink_Support: %s\n",
> +				        str_yes_no(drm_dp_sink_supports_fec(intel_connector->dp.fec_capability)));

Both of the above info is available already in the connector's
i915_dsc_fec_support debugfs entry. As I understood the aim is having
each CRTC / connector show its own properties, instead of combinining
all those into one debugfs entry (as this is done in i915_display_info).
Based on that I don't think more (duplicated) information should be
added here.

One issue with the i915_dsc_fec_support entry is that it doesn't show
the sink capabilities if the output isn't enabled on the connector, I
plan to follow up with a fix for that.

> +		}
>  		break;
>  	case DRM_MODE_CONNECTOR_HDMIA:
>  		if (encoder->type == INTEL_OUTPUT_HDMI ||
> -- 
> 2.25.1
>