[PATCH 7/7] drm/i915/display: Add handling for new "preferred color format" property

[Andri Yngvason]

From: Werner Sembach <wse at tuxedocomputers.com>

This commit implements the "preferred color format" drm property for the
Intel GPU driver.

Signed-off-by: Werner Sembach <wse at tuxedocomputers.com>
Co-developed-by: Andri Yngvason <andri at yngvason.is>
Signed-off-by: Andri Yngvason <andri at yngvason.is>
Tested-by: Andri Yngvason <andri at yngvason.is>
---
 drivers/gpu/drm/i915/display/intel_dp.c     | 16 ++++++++++------
 drivers/gpu/drm/i915/display/intel_dp_mst.c |  5 +++++
 drivers/gpu/drm/i915/display/intel_hdmi.c   | 12 +++++++++---
 3 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index c40fe8a847614..f241798660d0b 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2698,21 +2698,23 @@ intel_dp_compute_output_format(struct intel_encoder *encoder,
 	struct intel_connector *connector = intel_dp->attached_connector;
 	const struct drm_display_info *info = &connector->base.display_info;
 	const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
-	bool ycbcr_420_only;
+	bool ycbcr_420_output;
 	int ret;
 
-	ycbcr_420_only = drm_mode_is_420_only(info, adjusted_mode);
+	ycbcr_420_output = drm_mode_is_420_only(info, adjusted_mode) ||
+			   (conn_state->preferred_color_format == DRM_COLOR_FORMAT_YCBCR420 &&
+			    drm_mode_is_420_also(&connector->base.display_info, adjusted_mode));
 
-	if (ycbcr_420_only && !connector->base.ycbcr_420_allowed) {
+	crtc_state->sink_format = ycbcr_420_output ? INTEL_OUTPUT_FORMAT_YCBCR420 :
+						     INTEL_OUTPUT_FORMAT_RGB;
+
+	if (ycbcr_420_output && !connector->base.ycbcr_420_allowed) {
 		drm_dbg_kms(&i915->drm,
 			    "YCbCr 4:2:0 mode but YCbCr 4:2:0 output not possible. Falling back to RGB.\n");
 		crtc_state->sink_format = INTEL_OUTPUT_FORMAT_RGB;
-	} else {
-		crtc_state->sink_format = intel_dp_sink_format(connector, adjusted_mode);
 	}
 
 	crtc_state->output_format = intel_dp_output_format(connector, crtc_state->sink_format);
-
 	ret = intel_dp_compute_link_config(encoder, crtc_state, conn_state,
 					   respect_downstream_limits);
 	if (ret) {
@@ -5912,9 +5914,11 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect
 	intel_attach_broadcast_rgb_property(connector);
 	if (HAS_GMCH(dev_priv)) {
 		drm_connector_attach_max_bpc_property(connector, 6, 10);
+		drm_connector_attach_preferred_color_format_property(connector);
 		drm_connector_attach_active_color_format_property(connector);
 	} else if (DISPLAY_VER(dev_priv) >= 5) {
 		drm_connector_attach_max_bpc_property(connector, 6, 12);
+		drm_connector_attach_preferred_color_format_property(connector);
 		drm_connector_attach_active_color_format_property(connector);
 	}
 
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index e7574ca0604e6..4a850eb9b8d4d 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -1210,6 +1210,11 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
 		drm_dbg_kms(&dev_priv->drm, "[%s:%d] HDCP MST init failed, skipping.\n",
 			    connector->name, connector->base.id);
 
+	connector->preferred_color_format_property =
+		intel_dp->attached_connector->base.preferred_color_format_property;
+	if (connector->preferred_color_format_property)
+		drm_connector_attach_preferred_color_format_property(connector);
+
 	connector->active_color_format_property =
 		intel_dp->attached_connector->base.active_color_format_property;
 	if (connector->active_color_format_property)
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index ce0221f90de92..3030589d245d7 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2214,19 +2214,24 @@ static int intel_hdmi_compute_output_format(struct intel_encoder *encoder,
 	const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
 	const struct drm_display_info *info = &connector->base.display_info;
 	struct drm_i915_private *i915 = to_i915(connector->base.dev);
-	bool ycbcr_420_only = drm_mode_is_420_only(info, adjusted_mode);
+	bool ycbcr_420_output;
 	int ret;
 
+	ycbcr_420_output = drm_mode_is_420_only(info, adjusted_mode) ||
+			   (conn_state->preferred_color_format == DRM_COLOR_FORMAT_YCBCR420 &&
+			    drm_mode_is_420_also(&connector->base.display_info, adjusted_mode));
+
 	crtc_state->sink_format =
-		intel_hdmi_sink_format(crtc_state, connector, ycbcr_420_only);
+		intel_hdmi_sink_format(crtc_state, connector, ycbcr_420_output);
 
-	if (ycbcr_420_only && crtc_state->sink_format != INTEL_OUTPUT_FORMAT_YCBCR420) {
+	if (ycbcr_420_output && crtc_state->sink_format != INTEL_OUTPUT_FORMAT_YCBCR420) {
 		drm_dbg_kms(&i915->drm,
 			    "YCbCr 4:2:0 mode but YCbCr 4:2:0 output not possible. Falling back to RGB.\n");
 		crtc_state->sink_format = INTEL_OUTPUT_FORMAT_RGB;
 	}
 
 	crtc_state->output_format = intel_hdmi_output_format(crtc_state);
+
 	ret = intel_hdmi_compute_clock(encoder, crtc_state, respect_downstream_limits);
 	if (ret) {
 		if (crtc_state->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420 ||
@@ -2613,6 +2618,7 @@ intel_hdmi_add_properties(struct intel_hdmi *intel_hdmi, struct drm_connector *c
 
 	if (!HAS_GMCH(dev_priv)) {
 		drm_connector_attach_max_bpc_property(connector, 8, 12);
+		drm_connector_attach_preferred_color_format_property(connector);
 		drm_connector_attach_active_color_format_property(connector);
 	}
 }
-- 
2.43.0