drm/i915: Reject YCbCr output with degamma+gamma on pre-icl

Since the pipe CSC sits between the degamma and gamma LUTs there
is no way to make us it for RGB->YCbCr conversion when both LUTs
are also active. Simply reject such combos.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221026113906.10551-10-ville.syrjala@linux.intel.comReviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>

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

@@ -1556,7 +1556,14 @@ static int ivb_color_check(struct intel_crtc_state *crtc_state)
 	if (crtc_state->output_format != INTEL_OUTPUT_FORMAT_RGB &&
 	    crtc_state->hw.ctm) {
 		drm_dbg_kms(&i915->drm,
-			    "YCBCR and CTM together are not possible\n");
+			    "YCbCr and CTM together are not possible\n");
+		return -EINVAL;
+	}
+
+	if (crtc_state->output_format != INTEL_OUTPUT_FORMAT_RGB &&
+	    crtc_state->hw.degamma_lut && crtc_state->hw.gamma_lut) {
+		drm_dbg_kms(&i915->drm,
+			    "YCbCr and degamma+gamma together are not possible\n");
 		return -EINVAL;
 	}
 
@@ -1622,7 +1629,14 @@ static int glk_color_check(struct intel_crtc_state *crtc_state)
 	if (crtc_state->output_format != INTEL_OUTPUT_FORMAT_RGB &&
 	    crtc_state->hw.ctm) {
 		drm_dbg_kms(&i915->drm,
-			    "YCBCR and CTM together are not possible\n");
+			    "YCbCr and CTM together are not possible\n");
+		return -EINVAL;
+	}
+
+	if (crtc_state->output_format != INTEL_OUTPUT_FORMAT_RGB &&
+	    crtc_state->hw.degamma_lut && crtc_state->hw.gamma_lut) {
+		drm_dbg_kms(&i915->drm,
+			    "YCbCr and degamma+gamma together are not possible\n");
 		return -EINVAL;
 	}