From 7d6e9cb7b95165b40e7718b017c16b543d93411a Mon Sep 17 00:00:00 2001 From: "Jason-JH.Lin" Date: Wed, 20 Sep 2023 17:06:58 +0800 Subject: [PATCH] drm/mediatek: Add spinlock for setting vblank event in atomic_begin [ Upstream commit fe4c5f662097978b6c91c23a13c24ed92339a180 ] Add spinlock protection to avoid race condition on vblank event between mtk_drm_crtc_atomic_begin() and mtk_drm_finish_page_flip(). Fixes: 119f5173628a ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.") Signed-off-by: Jason-JH.Lin Suggested-by: AngeloGioacchino Del Regno Reviewed-by: Alexandre Mergnat Reviewed-by: Fei Shao Tested-by: Fei Shao Reviewed-by: AngeloGioacchino Del Regno Reviewed-by: CK Hu Link: https://patchwork.kernel.org/project/dri-devel/patch/20230920090658.31181-1-jason-jh.lin@mediatek.com/ Signed-off-by: Chun-Kuang Hu Signed-off-by: Sasha Levin --- drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c index 0a511d7..a033da2 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c @@ -747,6 +747,7 @@ static void mtk_drm_crtc_atomic_begin(struct drm_crtc *crtc, crtc); struct mtk_crtc_state *mtk_crtc_state = to_mtk_crtc_state(crtc_state); struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc); + unsigned long flags; if (mtk_crtc->event && mtk_crtc_state->base.event) DRM_ERROR("new event while there is still a pending event\n"); @@ -754,7 +755,11 @@ static void mtk_drm_crtc_atomic_begin(struct drm_crtc *crtc, if (mtk_crtc_state->base.event) { mtk_crtc_state->base.event->pipe = drm_crtc_index(crtc); WARN_ON(drm_crtc_vblank_get(crtc) != 0); + + spin_lock_irqsave(&crtc->dev->event_lock, flags); mtk_crtc->event = mtk_crtc_state->base.event; + spin_unlock_irqrestore(&crtc->dev->event_lock, flags); + mtk_crtc_state->base.event = NULL; } } -- 2.7.4