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From:   Chun-Kuang Hu <chunkuang.hu@kernel.org>
Date:   Mon, 12 Apr 2021 23:32:06 +0800
Message-ID: <CAAOTY_-qNeoZT1CorqhBrQe888tG21TF=LnPkUgymv=rQ8-YAA@mail.gmail.com>
Subject: Re: [PATCH -next] drm/mediatek: Fix PM reference leak in mtk_crtc_ddp_hw_init()
To:     Wang Li <wangli74@huawei.com>
Cc:     Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        DRI Development <dri-devel@lists.freedesktop.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        kernel-janitors@vger.kernel.org
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Hi, Wang:

Wang Li <wangli74@huawei.com> =E6=96=BC 2021=E5=B9=B44=E6=9C=8810=E6=97=A5 =
=E9=80=B1=E5=85=AD =E4=B8=8A=E5=8D=8811:31=E5=AF=AB=E9=81=93=EF=BC=9A
>
> pm_runtime_get_sync will increment pm usage counter even it failed.
> Forgetting to putting operation will result in reference leak here.
> Fix it by replacing it with pm_runtime_resume_and_get to keep usage
> counter balanced.

Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

>
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Wang Li <wangli74@huawei.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/me=
diatek/mtk_drm_crtc.c
> index 54ab3a324752..f1954242d8f6 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -259,7 +259,7 @@ static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *=
mtk_crtc)
>                 drm_connector_list_iter_end(&conn_iter);
>         }
>
> -       ret =3D pm_runtime_get_sync(crtc->dev->dev);
> +       ret =3D pm_runtime_resume_and_get(crtc->dev->dev);
>         if (ret < 0) {
>                 DRM_ERROR("Failed to enable power domain: %d\n", ret);
>                 return ret;
> --
> 2.17.1
>