[Intel-gfx] [PATCH 06/18] drm/i915/display13: Only enable legacy gamma for now

[Matt Roper]

The multi-segment gamma used on past platforms is gone and replaced by a
logarithmic LUT.  Until logarithmic LUT is enabled, let's just turn off
uapi color management (aside from legacy gamma) since it doesn't really
make sense to expose the full degamma and CTM when we only have limited
legacy gamma support to go with them.  Note that the hardware
programming of the degamma and CTM is unchanged except that the degamma
table now has 128 entries instead of just 33.

The output CSC used implicitly for RGB->YUV conversions is also
unchanged and will continue to function as expected.

Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
---
 drivers/gpu/drm/i915/i915_pci.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c
index e5e10484bf8d..fb28f3b24dd8 100644
--- a/drivers/gpu/drm/i915/i915_pci.c
+++ b/drivers/gpu/drm/i915/i915_pci.c
@@ -945,7 +945,18 @@ static const struct intel_device_info adl_s_info = {
 		BIT(TRANSCODER_C) | BIT(TRANSCODER_D),			\
 	.ddb_size = 4096,						\
 	.mbus_size = 2048,						\
-	.num_supported_dbuf_slices = 4,
+	.num_supported_dbuf_slices = 4,					\
+	/*								\
+	 * FIXME: Just enable legacy gamma (and no degamma/csc) until	\
+	 * logarithmic LUT is implemented.				\
+	 *								\
+	 * LEGACY_LUT_LENGTH = 256 entries				\
+	 *								\
+	 * Note that once logarithmic LUT is enabled and we re-enable	\
+	 * real color management, degamma_lut_size here should be set	\
+	 * to 128.							\
+	 */								\
+	.color = { .degamma_lut_size = 0, .gamma_lut_size = 256 }
 
 #undef GEN
 #undef PLATFORM
-- 
2.25.4