[PATCH 2/2] drm/i915: Implement WaSetupGtModeTdRowDispatch

[Daniel Vetter <daniel.vetter@ffwll.ch>]

I'm not really sure, since the w/a entry is as thin on details as
ever, and Bspec doesn't say anything about it. But I've figured only
dispatching to rows 0&1 instead of all four should be the right thing
for GT1.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/i915/i915_drv.h |    2 ++
 drivers/gpu/drm/i915/i915_reg.h |    3 ++-
 drivers/gpu/drm/i915/intel_pm.c |    5 +++++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 514aee8..84be497 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1196,6 +1196,8 @@ struct drm_i915_file_private {
 #define IS_IVB_GT1(dev)		((dev)->pci_device == 0x0156 || \
 				 (dev)->pci_device == 0x0152 ||	\
 				 (dev)->pci_device == 0x015a)
+#define IS_SNB_GT1(dev)		((dev)->pci_device == 0x0102 || \
+				 (dev)->pci_device == 0x0106)
 #define IS_VALLEYVIEW(dev)	(INTEL_INFO(dev)->is_valleyview)
 #define IS_HASWELL(dev)	(INTEL_INFO(dev)->is_haswell)
 #define IS_MOBILE(dev)		(INTEL_INFO(dev)->is_mobile)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index d72744e..4abf4f9 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -534,7 +534,8 @@
 # define MI_FLUSH_ENABLE				(1 << 12)
 
 #define GEN6_GT_MODE	0x20d0
-#define   GEN6_GT_MODE_HI	(1 << 9)
+#define   GEN6_GT_MODE_HI				(1 << 9)
+#define   GEN6_TD_FOUR_ROW_DISPATCH_DISABLE		(1 << 5)
 
 #define GFX_MODE	0x02520
 #define GFX_MODE_GEN7	0x0229c
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 2fddd17..89324a9 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3478,6 +3478,11 @@ static void gen6_init_clock_gating(struct drm_device *dev)
 	I915_WRITE(_3D_CHICKEN,
 		   _MASKED_BIT_ENABLE(_3D_CHICKEN_HIZ_PLANE_DISABLE_MSAA_4X_SNB));
 
+	/* WaSetupGtModeTdRowDispatch */
+	if (IS_SNB_GT1(dev))
+		I915_WRITE(GEN6_GT_MODE,
+			   _MASKED_BIT_ENABLE(GEN6_TD_FOUR_ROW_DISPATCH_DISABLE));
+
 	I915_WRITE(WM3_LP_ILK, 0);
 	I915_WRITE(WM2_LP_ILK, 0);
 	I915_WRITE(WM1_LP_ILK, 0);
-- 
1.7.10.4