drm/i915/dp: Check if DSC supports the given output_format

Go with DSC only if the given output_format is supported.

v2: Use drm helper to get DSC format support for sink.

v3: remove drm_dp_dsc_compute_bpp.

Cc: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230309062855.393087-3-suraj.kandpal@intel.com

drivers/gpu/drm/i915/display/intel_dp.c

@@ -1515,6 +1515,31 @@ static int intel_dp_dsc_compute_params(struct intel_encoder *encoder,
 	return drm_dsc_compute_rc_parameters(vdsc_cfg);
 }
 
+static bool intel_dp_dsc_supports_format(struct intel_dp *intel_dp,
+					 enum intel_output_format output_format)
+{
+	u8 sink_dsc_format;
+
+	switch (output_format) {
+	case INTEL_OUTPUT_FORMAT_RGB:
+		sink_dsc_format = DP_DSC_RGB;
+		break;
+	case INTEL_OUTPUT_FORMAT_YCBCR444:
+		sink_dsc_format = DP_DSC_YCbCr444;
+		break;
+	case INTEL_OUTPUT_FORMAT_YCBCR420:
+		if (min(intel_dp_source_dsc_version_minor(intel_dp),
+			intel_dp_sink_dsc_version_minor(intel_dp)) < 2)
+			return false;
+		sink_dsc_format = DP_DSC_YCbCr420_Native;
+		break;
+	default:
+		return false;
+	}
+
+	return drm_dp_dsc_sink_supports_format(intel_dp->dsc_dpcd, sink_dsc_format);
+}
+
 int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
 				struct intel_crtc_state *pipe_config,
 				struct drm_connector_state *conn_state,
@@ -1535,6 +1560,9 @@ int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
 	if (!intel_dp_supports_dsc(intel_dp, pipe_config))
 		return -EINVAL;
 
+	if (!intel_dp_dsc_supports_format(intel_dp, pipe_config->output_format))
+		return -EINVAL;
+
 	if (compute_pipe_bpp)
 		pipe_bpp = intel_dp_dsc_compute_bpp(intel_dp, conn_state->max_requested_bpc);
 	else