[Intel-gfx] [PATCH v4 1/4] drm/i915/dp: Check if DSC supports the given output_format

[Suraj Kandpal]

From: Ankit Nautiyal <ankit.k.nautiyal at intel.com>

Go with DSC only if the given output_format is supported.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 29 +++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 70b06806ec0d..c212171cced7 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1464,6 +1464,32 @@ 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 intel_dp->dsc_dpcd[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT] &
+	       sink_dsc_format;
+}
+
 static int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
 				       struct intel_crtc_state *pipe_config,
 				       struct drm_connector_state *conn_state,
@@ -1482,6 +1508,9 @@ static 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;
+
 	pipe_bpp = intel_dp_dsc_compute_bpp(intel_dp, conn_state->max_requested_bpc);
 
 	if (intel_dp->force_dsc_bpc) {
-- 
2.25.1