}
if (is_checked) {
- drm_vblank_put(drm_dev, crtc);
+ /*
+ * call drm_vblank_put only in case that drm_vblank_get was
+ * called.
+ */
+ if (atomic_read(&drm_dev->vblank_refcount[crtc]) > 0)
+ drm_vblank_put(drm_dev, crtc);
/*
* don't off vblank if vblank_disable_allowed is 1,