ddrm/i915/bdw: Disable centroid pixel perf optimization
BDW-A workaround
BDW Bug #1899532
v2: WARN on when not using preliminary HW support
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Jesse Barnes <jbarnes@virtuosugeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index b87945d5..ffd103a 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -5007,6 +5007,9 @@
#define HSW_ROW_CHICKEN3 0xe49c
#define HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE (1 << 6)
+#define HALF_SLICE_CHICKEN3 0xe184
+#define GEN8_CENTROID_PIXEL_OPT_DIS (1<<8)
+
#define G4X_AUD_VID_DID (dev_priv->info->display_mmio_offset + 0x62020)
#define INTEL_AUDIO_DEVCL 0x808629FB
#define INTEL_AUDIO_DEVBLC 0x80862801
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 8249be5..e036ba0 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5286,6 +5286,10 @@
/* FIXME(BDW): Check all the w/a, some might only apply to
* pre-production hw. */
+ WARN(!i915_preliminary_hw_support,
+ "GEN8_CENTROID_PIXEL_OPT_DIS not be needed for production\n");
+ I915_WRITE(HALF_SLICE_CHICKEN3,
+ _MASKED_BIT_ENABLE(GEN8_CENTROID_PIXEL_OPT_DIS));
I915_WRITE(GAMTARBMODE, _MASKED_BIT_ENABLE(ARB_MODE_BWGTLB_DISABLE));
/* WaSwitchSolVfFArbitrationPriority */