linux-kernel - Re: [PATCH 11/13] iommu/mediatek: Use builtin_platform_driver

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Message-ID: <1551278012.17917.51.camel@mhfsdcap03>
Date:   Wed, 27 Feb 2019 22:33:32 +0800
From:   Yong Wu <yong.wu@...iatek.com>
To:     Evan Green <evgreen@...omium.org>
CC:     <youlin.pei@...iatek.com>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@...r.kernel.org>,
        Nicolas Boichat <drinkcat@...omium.org>,
        Arnd Bergmann <arnd@...db.de>, <srv_heupstream@...iatek.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Joerg Roedel <joro@...tes.org>,
        Will Deacon <will.deacon@....com>,
        LKML <linux-kernel@...r.kernel.org>,
        Tomasz Figa <tfiga@...gle.com>,
        <iommu@...ts.linux-foundation.org>,
        Rob Herring <robh+dt@...nel.org>,
        <linux-mediatek@...ts.infradead.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        <yingjoe.chen@...iatek.com>, Robin Murphy <robin.murphy@....com>,
        <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH 11/13] iommu/mediatek: Use builtin_platform_driver

On Mon, 2019-02-25 at 15:56 -0800, Evan Green wrote:
> On Mon, Dec 31, 2018 at 8:53 PM Yong Wu <yong.wu@...iatek.com> wrote:
> >
> > MediaTek IOMMU should wait for smi larb which need wait for the
> > power domain(mtk-scpsys.c) and the multimedia ccf who both are
> > module init. Thus, subsys_initcall for MediaTek IOMMU is not helpful.
> > Switch to builtin_platform_driver.
> >
> > Meanwhile, the ".remove" can be removed. Move its content to
> > ".shutdown".
> >
> > Signed-off-by: Yong Wu <yong.wu@...iatek.com>
> > ---
> >  drivers/iommu/mtk_iommu.c    | 23 ++---------------------
> >  drivers/iommu/mtk_iommu_v1.c | 16 ++--------------
> >  2 files changed, 4 insertions(+), 35 deletions(-)
> >
> > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> > index 735ae8d..2798b12 100644
> > --- a/drivers/iommu/mtk_iommu.c
> > +++ b/drivers/iommu/mtk_iommu.c
> > @@ -690,7 +690,7 @@ static int mtk_iommu_probe(struct platform_device *pdev)
> >         return component_master_add_with_match(dev, &mtk_iommu_com_ops, match);
> >  }
> >
> > -static int mtk_iommu_remove(struct platform_device *pdev)
> > +static void mtk_iommu_shutdown(struct platform_device *pdev)
> >  {
> >         struct mtk_iommu_data *data = platform_get_drvdata(pdev);
> >
> > @@ -703,12 +703,6 @@ static int mtk_iommu_remove(struct platform_device *pdev)
> >         clk_disable_unprepare(data->bclk);
> >         devm_free_irq(&pdev->dev, data->irq, data);
> >         component_master_del(&pdev->dev, &mtk_iommu_com_ops);
> > -       return 0;
> > -}
> > -
> > -static void mtk_iommu_shutdown(struct platform_device *pdev)
> > -{
> > -       mtk_iommu_remove(pdev);
> 
> Is there a reason all these things are happening in shutdown()? Don't
> we normally just not clean things up and let the machine turn off?
> Normally I'm a big advocate of proper symmetric teardown, so it hurts
> a little to ask.

In this patch I change the driver to builtin driver. I guess the
"_remove" is not helpful now. thus I remove it.

About the shutdown, I don't have a special reason for it. I only want to
mute the m4u log when something go wrong in the shutdown flow.

> 
> _______________________________________________
> Linux-mediatek mailing list
> Linux-mediatek@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-mediatek

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