drm/i915: implement WaDisableVLVClockGating_VBIIssue on VLV
This allows us to get the right vblank interrupt frequency.
v2: pull in register definition
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Antti Koskipää <antti.koskipaa@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 871bfe4..10e6d6c 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3755,6 +3755,13 @@
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)