From fe4c5f662097978b6c91c23a13c24ed92339a180 Mon Sep 17 00:00:00 2001
From: "Jason-JH.Lin" <jason-jh.lin@mediatek.com>
Date: Wed, 20 Sep 2023 17:06:58 +0800
Subject: [PATCH] drm/mediatek: Add spinlock for setting vblank event in atomic_begin
Git-commit: fe4c5f662097978b6c91c23a13c24ed92339a180
Patch-mainline: v6.7-rc6
References: git-fixes
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@mediatek.com>
Suggested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: Fei Shao <fshao@chromium.org>
Tested-by: Fei Shao <fshao@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20230920090658.31181-1-jason-jh.lin@mediatek.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 c277b9fae950..0a7d60c191b8 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -788,6 +788,7 @@ 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");
@@ -795,7 +796,11 @@ 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;
}
}
--
2.35.3