[Intel-gfx] [PATCH 1/2] drm/i915/vlv:Implement WaDisable_RenderCache_OperationalFlush

[sourab.gupta at intel.com]

From: Akash Goel <akash.goel at intel.com>

In Valleyview, Operational flush cannot be enabled on
BWG A0 [Errata BWT006]

Signed-off-by: Akash Goel <akash.goel at intel.com>
Signed-off-by: Sourab Gupta <sourab.gupta at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h | 3 +++
 drivers/gpu/drm/i915/intel_pm.c | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 6174fda..8ddc3d5 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -970,6 +970,9 @@ enum punit_power_well {
 #define   ECO_GATING_CX_ONLY	(1<<3)
 #define   ECO_FLIP_DONE		(1<<0)
 
+#define GEN7_CACHE_MODE_0	0x07000 /* IVB+ only */
+#define GEN7_RC_OP_FLUSH_ENABLE (1<<0)
+
 #define CACHE_MODE_0_GEN7	0x7000 /* IVB+ */
 #define   HIZ_RAW_STALL_OPT_DISABLE (1<<2)
 #define CACHE_MODE_1		0x7004 /* IVB+ */
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 39f3238..97ff5e5 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5066,6 +5066,12 @@ static void valleyview_init_clock_gating(struct drm_device *dev)
 		   _MASKED_BIT_ENABLE(GEN7_MAX_PS_THREAD_DEP |
 				      GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE));
 
+	/* WaDisable_RenderCache_OperationalFlush:vlv
+	 * Clear bit 0, so we do a AND with the mask
+	 * to keep other bits the same */
+	I915_WRITE(GEN7_CACHE_MODE_0,  (I915_READ(GEN7_CACHE_MODE_0) |
+			  _MASKED_BIT_DISABLE(GEN7_RC_OP_FLUSH_ENABLE)));
+
 	/* WaForceL3Serialization:vlv */
 	I915_WRITE(GEN7_L3SQCREG4, I915_READ(GEN7_L3SQCREG4) &
 		   ~L3SQ_URB_READ_CAM_MATCH_DISABLE);
-- 
1.8.5.1