According to Bsepc, this should be set by default, but isn't. See vo1c.4 "Render Engine Command Streamer", Section 1.1.14.3 "3D_CHICKEN3" Bspec also says that we always need to set all mask bits. v2: Add comment about the mask bits wtf. Reviewed-by: Ben Widawsky <ben at bwidawsk.net> Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch> --- drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/intel_display.c | 4 ++++ 2 files changed, 5 insertions(+), 0 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 78171f7..cd2d2c7 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -439,6 +439,7 @@ */ # define _3D_CHICKEN2_WM_READ_PIPELINED (1 << 14) #define _3D_CHICKEN3 0x02090 +#define _3D_CHICKEN_SF_DISABLE_FASTCLIP_CULL (1 << 5) #define MI_MODE 0x0209c # define VS_TIMER_DISPATCH (1 << 6) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index b98c933..083c741 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -8575,6 +8575,10 @@ static void gen6_init_clock_gating(struct drm_device *dev) GEN6_RCPBUNIT_CLOCK_GATE_DISABLE | GEN6_RCCUNIT_CLOCK_GATE_DISABLE); + /* Bspec says we need to always set all mask bits. */ + I915_WRITE(_3D_CHICKEN, (0xFFFF << 16) | + _3D_CHICKEN_SF_DISABLE_FASTCLIP_CULL); + /* * According to the spec the following bits should be * set in order to enable memory self-refresh and fbc: -- 1.7.7.6
