drm/i915: fix WaDisablePSDDualDispatchEnable on VLV v2

Can prevent a hang when we get to tessellation.  We need to set bit 15
as well for this workaround.

v2: update changelog with accurate info

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 52d4f2d660db..0bb94d963b0a 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3899,8 +3899,10 @@ static void valleyview_init_clock_gating(struct drm_device *dev)
                    CHICKEN3_DGMG_REQ_OUT_FIX_DISABLE |
                    CHICKEN3_DGMG_DONE_FIX_DISABLE);
 
+        /* WaDisablePSDDualDispatchEnable */
         I915_WRITE(GEN7_HALF_SLICE_CHICKEN1,
-                   _MASKED_BIT_ENABLE(GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE));
+                   _MASKED_BIT_ENABLE(GEN7_MAX_PS_THREAD_DEP |
+                                      GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE));
 
         /* Apply the WaDisableRHWOOptimizationForRenderHang workaround. */
         I915_WRITE(GEN7_COMMON_SLICE_CHICKEN1,