[Intel-gfx] [PATCH] drm/i915/gt: Fixup tgl mocs for PTE tracking

[Chris Wilson]

Forcing mocs:1 [used for our winsys follows-pte mode] to be cached
caused display glitches. Though it is documented as deprecated (and so
likely behaves as uncached) use the follow-pte bit and force it out of
L3 cache.

Fixes: 4d8a5cfe3b13 ("drm/i915/gt: Initialize reserved and unspecified MOCS indices")
Testcase: igt/kms_frontbuffer_tracking
Testcase: igt/kms_big_fb
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Ayaz A Siddiqui <ayaz.siddiqui at intel.com>
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Cc: Matt Roper <matthew.d.roper at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
 drivers/gpu/drm/i915/gt/intel_mocs.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_mocs.c b/drivers/gpu/drm/i915/gt/intel_mocs.c
index 39179a3eee98..093b32db3428 100644
--- a/drivers/gpu/drm/i915/gt/intel_mocs.c
+++ b/drivers/gpu/drm/i915/gt/intel_mocs.c
@@ -243,8 +243,9 @@ static const struct drm_i915_mocs_entry tgl_mocs_table[] = {
 	 * only, __init_mocs_table() take care to program unused index with
 	 * this entry.
 	 */
-	MOCS_ENTRY(1, LE_3_WB | LE_TC_1_LLC | LE_LRUM(3),
-		   L3_3_WB),
+	MOCS_ENTRY(I915_MOCS_PTE,
+		   LE_0_PAGETABLE | LE_TC_0_PAGETABLE,
+		   L3_1_UC),
 	GEN11_MOCS_ENTRIES,
 
 	/* Implicitly enable L1 - HDC:L1 + L3 + LLC */
-- 
2.20.1