According to an internal workaround master list, we need to set bit 5 of register 9400 to avoid issues with color blits. Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch> --- drivers/gpu/drm/i915/i915_reg.h | 3 +++ drivers/gpu/drm/i915/intel_display.c | 4 ++++ 2 files changed, 7 insertions(+), 0 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 3886cf0..233dbd5 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -3727,6 +3727,9 @@ #define GT_FIFO_FREE_ENTRIES 0x120008 #define GT_FIFO_NUM_RESERVED_ENTRIES 20 +#define GEN6_UCGCTL1 0x9400 +# define GEN6_BLBUNIT_CLOCK_GATE_DISABLE (1 << 5) + #define GEN6_UCGCTL2 0x9404 # define GEN6_RCZUNIT_CLOCK_GATE_DISABLE (1 << 13) # define GEN6_RCPBUNIT_CLOCK_GATE_DISABLE (1 << 12) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index d514719..aa0c6df 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -8510,6 +8510,10 @@ static void gen6_init_clock_gating(struct drm_device *dev) I915_WRITE(WM2_LP_ILK, 0); I915_WRITE(WM1_LP_ILK, 0); + I915_WRITE(GEN6_UCGCTL1, + I915_READ(GEN6_UCGCTL1) | + GEN6_BLBUNIT_CLOCK_GATE_DISABLE); + /* According to the BSpec vol1g, bit 12 (RCPBUNIT) clock * gating disable must be set. Failure to set it results in * flickering pixels due to Z write ordering failures after -- 1.7.7.6
