drm/i915/bdw: Limit SDE poly depth FIFO to 2

BDW-A workaround

BDW Bug #1899155

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 4 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 1d557291fb28..c0b398572c2a 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -783,6 +783,7 @@
 #define _3D_CHICKEN3    0x02090
 #define  _3D_CHICKEN_SF_DISABLE_OBJEND_CULL             (1 << 10)
 #define  _3D_CHICKEN3_SF_DISABLE_FASTCLIP_CULL          (1 << 5)
+#define  _3D_CHICKEN_SDE_LIMIT_FIFO_POLY_DEPTH(x)       ((x)<<1)
 
 #define MI_MODE         0x0209c
 # define VS_TIMER_DISPATCH                              (1 << 6)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 7e0039e8c2d4..5dceb56f6ceb 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5294,6 +5294,9 @@ static void gen8_init_clock_gating(struct drm_device *dev)
                    _MASKED_BIT_ENABLE(GEN8_SAMPLER_POWER_BYPASS_DIS));
         I915_WRITE(GAMTARBMODE, _MASKED_BIT_ENABLE(ARB_MODE_BWGTLB_DISABLE));
 
+        I915_WRITE(_3D_CHICKEN3,
+                   _3D_CHICKEN_SDE_LIMIT_FIFO_POLY_DEPTH(2));
+
         /* WaSwitchSolVfFArbitrationPriority */
         I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) | HSW_ECOCHK_ARB_PRIO_SOL);