On Wed, Oct 29, 2014 at 03:12:43PM -0700, Kenneth Graunke wrote: > Haswell significantly improved the performance of sampler_c messages, > but the optimization appears to be off by default. Later platforms > remove this bit, and apparently always enable the optimization. > > Improves performance in "Counter Strike: Global Offensive" by 18% > at default settings on Iris Pro. No Piglit regressions. Nice. We need more bits like this ;) > > Signed-off-by: Kenneth Graunke <kenneth@xxxxxxxxxxxxx> > --- > 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 77fce96..340821a 100644 > --- a/drivers/gpu/drm/i915/i915_reg.h > +++ b/drivers/gpu/drm/i915/i915_reg.h > @@ -5952,6 +5952,7 @@ enum punit_power_well { > #define HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE (1 << 6) > > #define HALF_SLICE_CHICKEN3 0xe184 > +#define HSW_SAMPLE_C_PERFORMANCE (1<<9) > #define GEN8_CENTROID_PIXEL_OPT_DIS (1<<8) > #define GEN8_SAMPLER_POWER_BYPASS_DIS (1<<1) > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c > index 7a69eba..50c72a7 100644 > --- a/drivers/gpu/drm/i915/intel_pm.c > +++ b/drivers/gpu/drm/i915/intel_pm.c > @@ -5736,6 +5736,10 @@ static void haswell_init_clock_gating(struct drm_device *dev) > I915_WRITE(GEN7_GT_MODE, > GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4); > > + /* Make sample_c messages faster. */ I found a name for it in the w/a database. WaSampleCChickenBitEnable:hsw Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > + I915_WRITE(HALF_SLICE_CHICKEN3, > + _MASKED_BIT_ENABLE(HSW_SAMPLE_C_PERFORMANCE)); > + > /* WaSwitchSolVfFArbitrationPriority:hsw */ > I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) | HSW_ECOCHK_ARB_PRIO_SOL); > > -- > 2.1.2 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Ville Syrjälä Intel OTC _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx