drm/i915: enable vblank interrupt on ironlake

so far vblank interrupt on ironlake is disabled, this would cause
bad gfx performance if userspace calls drm_wait_vblank. This patch
enables vblank interrupt on ironlake and follows vblank get/put
model.

Signed-off-by: Li Peng <peng.li@intel.com>
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 45da78ef4a92..2cc489b6629e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1638,6 +1638,7 @@ static void ironlake_crtc_dpms(struct drm_crtc *crtc, int mode)
         case DRM_MODE_DPMS_OFF:
                 DRM_DEBUG_KMS("crtc %d dpms off\n", pipe);
 
+                drm_vblank_off(dev, pipe);
                 /* Disable display plane */
                 temp = I915_READ(dspcntr_reg);
                 if ((temp & DISPLAY_PLANE_ENABLE) != 0) {