Quoting from Bspec, 3D_CHICKEN1, bit 10 This bit needs to be set always to "1", Project: DevSNB " Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch> --- drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/intel_pm.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index f834804..d72744e 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -518,6 +518,7 @@ * the enables for writing to the corresponding low bit. */ #define _3D_CHICKEN 0x02084 +#define _3D_CHICKEN_HIZ_PLANE_DISABLE_MSAA_4X_SNB (1 << 10) #define _3D_CHICKEN2 0x0208c /* Disables pipelining of read flushes past the SF-WIZ interface. * Required on all Ironlake steppings according to the B-Spec, but the diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index abfff29..2fddd17 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -3474,6 +3474,10 @@ static void gen6_init_clock_gating(struct drm_device *dev) I915_READ(ILK_DISPLAY_CHICKEN2) | ILK_ELPIN_409_SELECT); + /* WaDisableHiZPlanesWhenMSAAEnabled */ + I915_WRITE(_3D_CHICKEN, + _MASKED_BIT_ENABLE(_3D_CHICKEN_HIZ_PLANE_DISABLE_MSAA_4X_SNB)); + I915_WRITE(WM3_LP_ILK, 0); I915_WRITE(WM2_LP_ILK, 0); I915_WRITE(WM1_LP_ILK, 0); -- 1.7.10.4
