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 <20230510164330.z2ygkl7vws6fci75@pengutronix.de>
In-Reply-To: <20230510164330.z2ygkl7vws6fci75@pengutronix.de>
From:   Chen-Yu Tsai <wenst@chromium.org>
Date:   Thu, 11 May 2023 13:50:23 +0800
Message-ID: <CAGXv+5HBM+eksJaxL2GqLfqSmK8vsQx5NXHfhe075HkOK3vjHw@mail.gmail.com>
Subject: Re: [PATCH] media: mediatek: vcodec: Convert mtk_vcodec_dec_hw
 platform remove callback
To:     =?UTF-8?Q?Uwe_Kleine=2DK=C3=B6nig?= 
        <u.kleine-koenig@pengutronix.de>
Cc:     Fei Shao <fshao@chromium.org>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Andrew-CT Chen <andrew-ct.chen@mediatek.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Tiffany Lin <tiffany.lin@mediatek.com>,
        Yunfei Dong <yunfei.dong@mediatek.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-media@vger.kernel.org, linux-mediatek@lists.infradead.org,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Pavel Machek <pavel@ucw.cz>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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On Thu, May 11, 2023 at 12:43=E2=80=AFAM Uwe Kleine-K=C3=B6nig
<u.kleine-koenig@pengutronix.de> wrote:
>
> [expanding the audience a bit for more expertise]
>
> Hello,
>
> On Wed, May 10, 2023 at 11:31:35PM +0800, Fei Shao wrote:
> > This aligns with [1] and converts the platform remove callback to
> > .remove_new(), which returns void.
> >
> > [1]: commit a3afc5b10661 ("media: mtk_vcodec_dec_drv: Convert to
> >      platform remove callback returning void")
> >
> > Signed-off-by: Fei Shao <fshao@chromium.org>
> >
> > ---
> >
> >  drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec_hw.c | 6 ++----
> >  1 file changed, 2 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec_hw.c=
 b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec_hw.c
> > index b753bf54ebd9..bd5743723da6 100644
> > --- a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec_hw.c
> > +++ b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec_hw.c
> > @@ -193,16 +193,14 @@ static int mtk_vdec_hw_probe(struct platform_devi=
ce *pdev)
> >       return ret;
> >  }
> >
> > -static int mtk_vdec_hw_remove(struct platform_device *pdev)
> > +static void mtk_vdec_hw_remove(struct platform_device *pdev)
> >  {
> >       pm_runtime_disable(&pdev->dev);
> > -
> > -     return 0;
> >  }
> >
> >  static struct platform_driver mtk_vdec_driver =3D {
> >       .probe  =3D mtk_vdec_hw_probe,
> > -     .remove =3D mtk_vdec_hw_remove,
> > +     .remove_new =3D mtk_vdec_hw_remove,
> >       .driver =3D {
> >               .name   =3D "mtk-vdec-comp",
> >               .of_match_table =3D mtk_vdec_hw_match,
>
> While the patch looks fine, I wonder if having a remove callback just to
> do pm_runtime_disable() is worth keeping it. Doesn't the core care for
> things like that? I grepped a bit around, device_unbind_cleanup() is
> called after device_remove() which calls pm_runtime_reinit(). Does that
> mean calling pm_runtime_disable in .remove() is useless? In that case,
> you could just drop the .remove() callback.

Maybe just switch to devm_pm_runtime_enable() on the enable side?

ChenYu