drm/mediatek: handle events when enabling/disabling crtc

The driver currently handles vblank events only when updating planes on
an already enabled CRTC. The atomic update API however allows requesting
an event when enabling or disabling a CRTC. This currently leads to
event objects being leaked in the kernel and to events not being sent
out. Fix it.
Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
Signed-off-by: CK Hu <ck.hu@mediatek.com>

drivers/gpu/drm/mediatek/mtk_drm_crtc.c

@@ -328,6 +328,7 @@ static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
 static void mtk_crtc_ddp_hw_fini(struct mtk_drm_crtc *mtk_crtc)
 {
 	struct drm_device *drm = mtk_crtc->base.dev;
+	struct drm_crtc *crtc = &mtk_crtc->base;
 	int i;
 
 	DRM_DEBUG_DRIVER("%s\n", __func__);
@@ -353,6 +354,13 @@ static void mtk_crtc_ddp_hw_fini(struct mtk_drm_crtc *mtk_crtc)
 	mtk_disp_mutex_unprepare(mtk_crtc->mutex);
 
 	pm_runtime_put(drm->dev);
+
+	if (crtc->state->event && !crtc->state->active) {
+		spin_lock_irq(&crtc->dev->event_lock);
+		drm_crtc_send_vblank_event(crtc, crtc->state->event);
+		crtc->state->event = NULL;
+		spin_unlock_irq(&crtc->dev->event_lock);
+	}
 }
 
 static void mtk_crtc_ddp_config(struct drm_crtc *crtc)