diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 6b3ce6d3..7998ee6 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -429,15 +429,21 @@
 
 	spin_lock_irqsave(&dev->vbl_lock, irqflags);
 	/* Going from 0->1 means we have to enable interrupts again */
-	if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1 &&
-	    !dev->vblank_enabled[crtc]) {
-		ret = dev->driver->enable_vblank(dev, crtc);
-		DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc, ret);
-		if (ret)
+	if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) {
+		if (!dev->vblank_enabled[crtc]) {
+			ret = dev->driver->enable_vblank(dev, crtc);
+			DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc, ret);
+			if (ret)
+				atomic_dec(&dev->vblank_refcount[crtc]);
+			else {
+				dev->vblank_enabled[crtc] = 1;
+				drm_update_vblank_count(dev, crtc);
+			}
+		}
+	} else {
+		if (!dev->vblank_enabled[crtc]) {
 			atomic_dec(&dev->vblank_refcount[crtc]);
-		else {
-			dev->vblank_enabled[crtc] = 1;
-			drm_update_vblank_count(dev, crtc);
+			ret = -EINVAL;
 		}
 	}
 	spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
@@ -464,6 +470,18 @@
 }
 EXPORT_SYMBOL(drm_vblank_put);
 
+void drm_vblank_off(struct drm_device *dev, int crtc)
+{
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&dev->vbl_lock, irqflags);
+	DRM_WAKEUP(&dev->vbl_queue[crtc]);
+	dev->vblank_enabled[crtc] = 0;
+	dev->last_vblank[crtc] = dev->driver->get_vblank_counter(dev, crtc);
+	spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+}
+EXPORT_SYMBOL(drm_vblank_off);
+
 /**
  * drm_vblank_pre_modeset - account for vblanks across mode sets
  * @dev: DRM device