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References: <20230822132646.9811-1-jason-jh.lin@mediatek.com> <CAC=S1njUVqt969Wv+dMc5wD3Uyu-2Cm4qCUwkp7kfeG_uBbpVw@mail.gmail.com>
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From:   Fei Shao <fshao@chromium.org>
Date:   Wed, 13 Sep 2023 15:54:18 +0800
Message-ID: <CAC=S1nhhAevMct0SoipCRpVmHmMGEuvu2yKmkjuVVUpeZxZ5ug@mail.gmail.com>
Subject: Re: [PATCH] drm/mediatek: Add spinlock for setting vblank event in atomic_begin
To:     "Jason-JH.Lin" <jason-jh.lin@mediatek.com>
Cc:     Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Alexandre Mergnat <amergnat@baylibre.com>,
        Eugen Hristev <eugen.hristev@collabora.com>,
        Jason-ch Chen <jason-ch.chen@mediatek.com>,
        Johnson Wang <johnson.wang@mediatek.com>,
        Singo Chang <singo.chang@mediatek.com>,
        Nancy Lin <nancy.lin@mediatek.com>,
        Shawn Sung <shawn.sung@mediatek.com>,
        dri-devel@lists.freedesktop.org,
        linux-mediatek@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Project_Global_Chrome_Upstream_Group@mediatek.com
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On Thu, Aug 31, 2023 at 3:12=E2=80=AFPM Fei Shao <fshao@chromium.org> wrote=
:
>
> On Tue, Aug 22, 2023 at 10:27=E2=80=AFPM Jason-JH.Lin <jason-jh.lin@media=
tek.com> wrote:
> >
> > 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 MT8=
173.")
> > Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
>
> Reviewed-by: Fei Shao <fshao@chromium.org>

Also, I verified that this fixes a real world system hang issue on the
MT8195 Chromebook.

Tested-by: Fei Shao <fshao@chromium.org>