From: Ville Syrjälä <[email protected]> BSpec recommends using 8x4 hashing mode when MSAA is used. But in practice 16x4 seems to have a slight edge in performance (on IVB and HSW at least). So just use 16x4.
Signed-off-by: Ville Syrjälä <[email protected]> --- drivers/gpu/drm/i915/intel_pm.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index ba5fee4..c3a1362 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -4826,6 +4826,13 @@ static void gen8_init_clock_gating(struct drm_device *dev) I915_WRITE(GEN7_FF_THREAD_MODE, I915_READ(GEN7_FF_THREAD_MODE) & ~(GEN8_FF_DS_REF_CNT_FFME | GEN7_FF_VS_REF_CNT_FFME)); + + /* + * BSpec recommends 8x4 when MSAA is used, + * however in practice 16x4 seems fastest. + */ + I915_WRITE(GEN7_GT_MODE, + GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4); } static void haswell_init_clock_gating(struct drm_device *dev) -- 1.8.3.2 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
