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>
---
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 b6fa4ad2f94d..cab4fe092f13 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -744,6 +744,7 @@ 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");
@@ -751,7 +752,11 @@ 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;
}
}
--
2.18.0
