5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
[ 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 <jason-jh.lin@xxxxxxxxxxxx>
Suggested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Reviewed-by: Alexandre Mergnat <amergnat@xxxxxxxxxxxx>
Reviewed-by: Fei Shao <fshao@xxxxxxxxxxxx>
Tested-by: Fei Shao <fshao@xxxxxxxxxxxx>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20230920090658.31181-1-jason-jh.lin@xxxxxxxxxxxx/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 f2264633be1b7..d6781e54b3356 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -680,6 +680,7 @@ 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");
@@ -687,7 +688,11 @@ 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;
}
}
--
2.43.0
