drm/exynos: release pending pageflip events when closed

We should release pending pageflip events when closed. If not, they will
be dangling events.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/exynos/exynos_drm_drv.c

@@ -147,8 +147,22 @@ static int exynos_drm_unload(struct drm_device *dev)
 static void exynos_drm_preclose(struct drm_device *dev,
 					struct drm_file *file)
 {
+	struct exynos_drm_private *private = dev->dev_private;
+	struct drm_pending_vblank_event *e, *t;
+	unsigned long flags;
+
 	DRM_DEBUG_DRIVER("%s\n", __FILE__);
 
+	/* release events of current file */
+	spin_lock_irqsave(&dev->event_lock, flags);
+	list_for_each_entry_safe(e, t, &private->pageflip_event_list,
+			base.link) {
+		if (e->base.file_priv == file) {
+			list_del(&e->base.link);
+			e->base.destroy(&e->base);
+		}
+	}
+	spin_unlock_irqrestore(&dev->event_lock, flags);
 }
 
 static void exynos_drm_postclose(struct drm_device *dev, struct drm_file *file)