diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 17283e8920378..d57405050554f 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -547,19 +547,20 @@ static void drm_vblank_init_release(struct drm_device *dev, void *ptr)
 int drm_vblank_init(struct drm_device *dev)
 {
 	int ret;
-	unsigned int num_crtcs = dev->mode_config.num_crtc;
-	unsigned int i;
+	struct drm_crtc *crtc;
 
 	spin_lock_init(&dev->vbl_lock);
 	spin_lock_init(&dev->vblank_time_lock);
 
-	dev->vblank = drmm_kcalloc(dev, num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
+	dev->vblank = drmm_kcalloc(dev, dev->mode_config.num_crtc,
+				   sizeof(*dev->vblank), GFP_KERNEL);
 	if (!dev->vblank)
 		return -ENOMEM;
 
 	dev->has_hw_vblank = true;
 
-	for (i = 0; i < num_crtcs; i++) {
+	drm_for_each_crtc(crtc, dev) {
+		unsigned int i = crtc->index;
 		struct drm_vblank_crtc *vblank = drm_vblank_crtc(dev, i);
 
 		vblank->dev = dev;