From 1e3ea8d2bad845e512ee3430323206d4f8ec9cc2 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 cc3cb5b63d44..1eaf513166a1 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c @@ -582,6 +582,7 @@ static void mtk_drm_crtc_atomic_begin(struct drm_crtc *crtc, { struct mtk_crtc_state *state = to_mtk_crtc_state(crtc->state); struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc); + unsigned long flags; if (mtk_crtc->event && state->base.event) DRM_ERROR("new event while there is still a pending event\n"); @@ -589,7 +590,11 @@ static void mtk_drm_crtc_atomic_begin(struct drm_crtc *crtc, if (state->base.event) { 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 = state->base.event; + spin_unlock_irqrestore(&crtc->dev->event_lock, flags); + state->base.event = NULL; } }