drm/mediatek: Use spin_lock_irqsave() for CRTC event lock

Use the state-aware spin_lock_irqsave() and spin_unlock_irqrestore()
to avoid unconditionally re-enabling the local interrupts.

Fixes: 411f5c1e ("drm/mediatek: handle events when enabling/disabling crtc")
Signed-off-by: Fei Shao <fshao@chromium.org>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20240828101511.3269822-1-fshao@chromium.org/Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

drivers/gpu/drm/mediatek/mtk_crtc.c

@@ -429,6 +429,7 @@ static void mtk_crtc_ddp_hw_fini(struct mtk_crtc *mtk_crtc)
 {
 	struct drm_device *drm = mtk_crtc->base.dev;
 	struct drm_crtc *crtc = &mtk_crtc->base;
+	unsigned long flags;
 	int i;
 
 	for (i = 0; i < mtk_crtc->ddp_comp_nr; i++) {
@@ -460,10 +461,10 @@ static void mtk_crtc_ddp_hw_fini(struct mtk_crtc *mtk_crtc)
 	pm_runtime_put(drm->dev);
 
 	if (crtc->state->event && !crtc->state->active) {
-		spin_lock_irq(&crtc->dev->event_lock);
+		spin_lock_irqsave(&crtc->dev->event_lock, flags);
 		drm_crtc_send_vblank_event(crtc, crtc->state->event);
 		crtc->state->event = NULL;
-		spin_unlock_irq(&crtc->dev->event_lock);
+		spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
 	}
 }