[Intel-gfx] [PATCH v2 12/12] drm/i915/dp: Disable DFP RGB->YCbCr conversion for now

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

We lack sufficient state tracking to figure out whether
we want the DFP to perform the RGB->YCbCr conversion for us
or not. So currently we are blindly just enabling that all the
time when supported by the DFP. That is nonsense. So until
we imporve our state tracking for this just disable the feature.

Cc: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
Cc: Uma Shankar <uma.shankar at intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index d3d458b3267d..a57581198a47 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1180,6 +1180,7 @@ static bool intel_dp_supports_dsc(struct intel_dp *intel_dp,
 static bool intel_dp_is_ycbcr420(struct intel_dp *intel_dp,
 				 const struct intel_crtc_state *crtc_state)
 {
+	/* FIXME see intel_dp_update_420() regarding rgb_to_ycbcr */
 	return crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 ||
 		(crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR444 &&
 		 intel_dp->dfp.ycbcr_444_to_420);
@@ -2574,6 +2575,7 @@ void intel_dp_configure_protocol_converter(struct intel_dp *intel_dp,
 			    "Failed to %s protocol converter YCbCr 4:2:0 conversion mode\n",
 			    str_enable_disable(intel_dp->dfp.ycbcr_444_to_420));
 
+	/* FIXME see intel_dp_update_420() regarding rgb_to_ycbcr */
 	tmp = intel_dp->dfp.rgb_to_ycbcr ?
 		DP_CONVERSION_BT709_RGB_YCBCR_ENABLE : 0;
 
@@ -4430,6 +4432,14 @@ intel_dp_update_420(struct intel_dp *intel_dp)
 	rgb_to_ycbcr = drm_dp_downstream_rgb_to_ycbcr_conversion(intel_dp->dpcd,
 								 intel_dp->downstream_ports,
 								 DP_DS_HDMI_BT709_RGB_YCBCR_CONV);
+	/*
+	 * FIXME need to actually track whether we're really
+	 * going to be doing the RGB->YCbCr connversion or not.
+	 * We can't tell by simply looking at intel_dp->dfp.rgb_to_ycbcr.
+	 * Readout is going to annoying due to having to read that
+	 * state from external hardware that may vanish at any time :(
+	 */
+	rgb_to_ycbcr = false;
 
 	if (DISPLAY_VER(i915) >= 11) {
 		/* Let PCON convert from RGB->YCbCr if possible */
-- 
2.34.1