[PATCH v2 4/4] drm/i915/3dlut: disable 3D LUT if unsupported

["Michał Grzelak" <michal.grzelak@intel.com>]

XE2LPD_DE_CAP_3DLUT_MASK is defined but never used.

Check DE_CAP with the mask whether 3D LUT is disabled for LNL+. Reset
has_3dlut if that is the case.

Bspec: 71161
Cc: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Cc: <stable@vger.kernel.org>
Fixes: 6d181a288e64 ("drm/i915/xe2lpd: update the dsc feature capability")
Signed-off-by: Michał Grzelak <michal.grzelak@intel.com>
---
 drivers/gpu/drm/i915/display/intel_display_device.c | 4 ++++
 drivers/gpu/drm/i915/display/intel_display_regs.h   | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c b/drivers/gpu/drm/i915/display/intel_display_device.c
index a2bea5ac59cf..d4e52e627b34 100644
--- a/drivers/gpu/drm/i915/display/intel_display_device.c
+++ b/drivers/gpu/drm/i915/display/intel_display_device.c
@@ -1940,6 +1940,10 @@ static void __intel_display_device_info_runtime_init(struct intel_display *displ
 	if (DISPLAY_VER(display) >= 20) {
 		u32 cap = intel_de_read(display, XE2LPD_DE_CAP);
 
+		if (REG_FIELD_GET(XE2LPD_DE_CAP_3DLUT_MASK, cap) ==
+		    XE2LPD_DE_CAP_3DLUT_REMOVED)
+			display_runtime->has_3dlut = 0;
+
 		if (REG_FIELD_GET(XE2LPD_DE_CAP_DSC_MASK, cap) ==
 		    XE2LPD_DE_CAP_DSC_REMOVED)
 			display_runtime->has_dsc = 0;
diff --git a/drivers/gpu/drm/i915/display/intel_display_regs.h b/drivers/gpu/drm/i915/display/intel_display_regs.h
index 740331ead20a..78b9e6008828 100644
--- a/drivers/gpu/drm/i915/display/intel_display_regs.h
+++ b/drivers/gpu/drm/i915/display/intel_display_regs.h
@@ -1773,6 +1773,7 @@
 
 #define XE2LPD_DE_CAP			_MMIO(0x41100)
 #define   XE2LPD_DE_CAP_3DLUT_MASK	REG_GENMASK(31, 30)
+#define   XE2LPD_DE_CAP_3DLUT_REMOVED	1
 #define   XE2LPD_DE_CAP_DSC_MASK	REG_GENMASK(29, 28)
 #define   XE2LPD_DE_CAP_DSC_REMOVED	1
 #define   XE2LPD_DE_CAP_SCALER_MASK	REG_GENMASK(27, 26)
-- 
2.45.2