From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> commit be33805c65297611971003d72e7f9235e23ec84d upstream. 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. Testcase: igt/kms_frontbuffer_tracking Testcase: igt/kms_big_fb Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Ayaz A Siddiqui <ayaz.siddiqui@xxxxxxxxx> Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> Cc: Matt Roper <matthew.d.roper@xxxxxxxxx> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20201015122138.30161-4-chris@xxxxxxxxxxxxxxxxxx (cherry picked from commit a04ac827366594c7244f60e9be79fcb404af69f0) Fixes: 849c0fe9e831 ("drm/i915/gt: Initialize reserved and unspecified MOCS indices") Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> [Rodrigo: Updated Fixes tag] Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/gt/intel_mocs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- 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 * 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 */
