drm/i915/skl: drop workarounds for A0 and B0 revisions

Pre-production hardware is not supported.

Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/7929af62a68504c84038a8db1625bd96ebaa9e6f.1474034059.git.jani.nikula@intel.com
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 7a74750..2faf64f 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -851,15 +851,13 @@
 	WA_SET_BIT_MASKED(HALF_SLICE_CHICKEN3,
 			  GEN9_DISABLE_OCL_OOB_SUPPRESS_LOGIC);
 
-	/* WaDisableDgMirrorFixInHalfSliceChicken5:skl,bxt */
-	if (IS_SKL_REVID(dev_priv, 0, SKL_REVID_B0) ||
-	    IS_BXT_REVID(dev_priv, 0, BXT_REVID_A1))
+	/* WaDisableDgMirrorFixInHalfSliceChicken5:bxt */
+	if (IS_BXT_REVID(dev_priv, 0, BXT_REVID_A1))
 		WA_CLR_BIT_MASKED(GEN9_HALF_SLICE_CHICKEN5,
 				  GEN9_DG_MIRROR_FIX_ENABLE);
 
-	/* WaSetDisablePixMaskCammingAndRhwoInCommonSliceChicken:skl,bxt */
-	if (IS_SKL_REVID(dev_priv, 0, SKL_REVID_B0) ||
-	    IS_BXT_REVID(dev_priv, 0, BXT_REVID_A1)) {
+	/* WaSetDisablePixMaskCammingAndRhwoInCommonSliceChicken:bxt */
+	if (IS_BXT_REVID(dev_priv, 0, BXT_REVID_A1)) {
 		WA_SET_BIT_MASKED(GEN7_COMMON_SLICE_CHICKEN1,
 				  GEN9_RHWO_OPTIMIZATION_DISABLE);
 		/*
@@ -1023,15 +1021,8 @@
 			   GEN8_LQSC_RO_PERF_DIS);
 
 	/* WaEnableGapsTsvCreditFix:skl */
-	if (IS_SKL_REVID(dev_priv, SKL_REVID_C0, REVID_FOREVER)) {
-		I915_WRITE(GEN8_GARBCNTL, (I915_READ(GEN8_GARBCNTL) |
-					   GEN9_GAPS_TSV_CREDIT_DISABLE));
-	}
-
-	/* WaDisablePowerCompilerClockGating:skl */
-	if (IS_SKL_REVID(dev_priv, SKL_REVID_B0, SKL_REVID_B0))
-		WA_SET_BIT_MASKED(HIZ_CHICKEN,
-				  BDW_HIZ_POWER_COMPILER_CLOCK_GATING_DISABLE);
+	I915_WRITE(GEN8_GARBCNTL, (I915_READ(GEN8_GARBCNTL) |
+				   GEN9_GAPS_TSV_CREDIT_DISABLE));
 
 	/* WaBarrierPerformanceFixDisable:skl */
 	if (IS_SKL_REVID(dev_priv, SKL_REVID_C0, SKL_REVID_D0))