drm/exynos: remove unnecessary codes

This patch removes exynos_drm_crtc_cancel_page_flip call
when drm is closed because at that time, events will be released
by drm_events_release function.

Changelog v1:
- remove exynos_drm_crtc_cancel_page_flip function also because
  this funtion isn't used anymore.
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_crtc.c

@@ -203,23 +203,3 @@ void exynos_drm_crtc_te_handler(struct drm_crtc *crtc)
 	if (exynos_crtc->ops->te_handler)
 		exynos_crtc->ops->te_handler(exynos_crtc);
 }
-
-void exynos_drm_crtc_cancel_page_flip(struct drm_crtc *crtc,
-					struct drm_file *file)
-{
-	struct drm_pending_vblank_event *e;
-	unsigned long flags;
-
-	spin_lock_irqsave(&crtc->dev->event_lock, flags);
-
-	e = crtc->state->event;
-	if (e && e->base.file_priv == file)
-		crtc->state->event = NULL;
-	else
-		e = NULL;
-
-	spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
-
-	if (e)
-		drm_event_cancel_free(crtc->dev, &e->base);
-}

drivers/gpu/drm/exynos/exynos_drm_crtc.h

@@ -40,8 +40,4 @@ int exynos_drm_crtc_get_pipe_from_type(struct drm_device *drm_dev,
  */
 void exynos_drm_crtc_te_handler(struct drm_crtc *crtc);
 
-/* This function cancels a page flip request. */
-void exynos_drm_crtc_cancel_page_flip(struct drm_crtc *crtc,
-					struct drm_file *file);
-
 #endif

drivers/gpu/drm/exynos/exynos_drm_drv.c

@@ -307,12 +307,7 @@ static int exynos_drm_open(struct drm_device *dev, struct drm_file *file)
 static void exynos_drm_preclose(struct drm_device *dev,
 					struct drm_file *file)
 {
-	struct drm_crtc *crtc;
-
 	exynos_drm_subdrv_close(dev, file);
-
-	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head)
-		exynos_drm_crtc_cancel_page_flip(crtc, file);
 }
 
 static void exynos_drm_postclose(struct drm_device *dev, struct drm_file *file)