[Intel-gfx] [PATCH 06/12] drm/i915: implement WaDisableVLVClockGating_VBIIssue on VLV

[Jesse Barnes]

This allows us to get the right vblank interrupt frequency.

Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/i915/intel_pm.c |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 0659317..828629b 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3687,6 +3687,13 @@ static void valleyview_init_clock_gating(struct drm_device *dev)
 		   PIPEA_HLINE_INT_EN | PIPEA_VBLANK_INT_EN |
 		   SPRITEB_FLIPDONE_INT_EN | SPRITEA_FLIPDONE_INT_EN |
 		   PLANEA_FLIPDONE_INT_EN);
+
+	/*
+	 * WaDisableVLVClockGating_VBIIssue
+	 * Disable clock gating on th GCFG unit to prevent a delay
+	 * in the reporting of vblank events.
+	 */
+	I915_WRITE(VLV_GUNIT_CLOCK_GATE, GCFG_DIS);
 }
 
 static void g4x_init_clock_gating(struct drm_device *dev)
-- 
1.7.9.5