[Intel-gfx] [PATCH 1/2] drm/i915: Fix legacy gamma mode for ICL

[Ville Syrjala]

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

We must remember to actually enable the post CSC gamma if
we expect the legacy LUT to work. Seems to fix NV12 crc
tests on the SDR planes. Curiously we apparently managed to
get 100% match for the HDR planes even without chopping
off the low bits.

Cc: Uma Shankar <uma.shankar at intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_color.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_color.c b/drivers/gpu/drm/i915/intel_color.c
index 0173967ed593..7dacb1a2fc95 100644
--- a/drivers/gpu/drm/i915/intel_color.c
+++ b/drivers/gpu/drm/i915/intel_color.c
@@ -792,6 +792,9 @@ int intel_color_check(struct intel_crtc_state *crtc_state)
 	if (!crtc_state->gamma_enable ||
 	    crtc_state_is_legacy_gamma(crtc_state)) {
 		crtc_state->gamma_mode = GAMMA_MODE_MODE_8BIT;
+		if (INTEL_GEN(dev_priv) >= 11 &&
+		    crtc_state->gamma_enable)
+			crtc_state->gamma_mode |= POST_CSC_GAMMA_ENABLE;
 		return 0;
 	}
 
-- 
2.19.2