linux-kernel - Re: [PATCH v8 09/12] media: mtk-vcodec: Get rid of mtk_smi_larb_get/put

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Date:   Thu, 7 Oct 2021 10:57:01 +0800
From:   Yong Wu <yong.wu@...iatek.com>
To:     Dafna Hirschfeld <dafna.hirschfeld@...labora.com>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Joerg Roedel <joro@...tes.org>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>,
        David Airlie <airlied@...ux.ie>,
        "Mauro Carvalho Chehab" <mchehab@...nel.org>
CC:     Evan Green <evgreen@...omium.org>,
        Robin Murphy <robin.murphy@....com>,
        Tomasz Figa <tfiga@...omium.org>,
        Will Deacon <will.deacon@....com>,
        <linux-mediatek@...ts.infradead.org>,
        <srv_heupstream@...iatek.com>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <iommu@...ts.linux-foundation.org>, <youlin.pei@...iatek.com>,
        Matthias Kaehlcke <mka@...omium.org>, <anan.sun@...iatek.com>,
        <yi.kuo@...iatek.com>, <acourbot@...omium.org>,
        <linux-media@...r.kernel.org>, <dri-devel@...ts.freedesktop.org>,
        "Daniel Vetter" <daniel@...ll.ch>,
        Chun-Kuang Hu <chunkuang.hu@...nel.org>,
        "Philipp Zabel" <p.zabel@...gutronix.de>,
        Tiffany Lin <tiffany.lin@...iatek.com>,
        Hsin-Yi Wang <hsinyi@...omium.org>,
        Eizan Miyamoto <eizan@...omium.org>,
        <anthony.huang@...iatek.com>,
        Frank Wunderlich <frank-w@...lic-files.de>,
        Irui Wang <irui.wang@...iatek.com>
Subject: Re: [PATCH v8 09/12] media: mtk-vcodec: Get rid of
 mtk_smi_larb_get/put

On Thu, 2021-09-30 at 12:57 +0200, Dafna Hirschfeld wrote:
> 
> On 30.09.21 05:28, Yong Wu wrote:
> > Hi Dafna,
> > 
> > Thanks very much for the review.
> > 
> > On Wed, 2021-09-29 at 14:13 +0200, Dafna Hirschfeld wrote:
> > > 
> > > On 29.09.21 03:37, Yong Wu wrote:
> > > > MediaTek IOMMU has already added the device_link between the
> > > > consumer
> > > > and smi-larb device. If the vcodec device call the
> > > > pm_runtime_get_sync,
> > > > the smi-larb's pm_runtime_get_sync also be called
> > > > automatically.
> > > > 
> > > > CC: Tiffany Lin <tiffany.lin@...iatek.com>
> > > > CC: Irui Wang <irui.wang@...iatek.com>
> > > > Signed-off-by: Yong Wu <yong.wu@...iatek.com>
> > > > Reviewed-by: Evan Green <evgreen@...omium.org>
> > > > Acked-by: Tiffany Lin <tiffany.lin@...iatek.com>
> > > > Reviewed-by: Dafna Hirschfeld <dafna.hirschfeld@...labora.com>
> > > > ---
> > > >    .../platform/mtk-vcodec/mtk_vcodec_dec_pm.c   | 37 +++----
> > > > -------
> > > > --
> > > >    .../platform/mtk-vcodec/mtk_vcodec_drv.h      |  3 --
> > > >    .../platform/mtk-vcodec/mtk_vcodec_enc.c      |  1 -
> > > >    .../platform/mtk-vcodec/mtk_vcodec_enc_pm.c   | 44 +++----
> > > > -------

[snip]

> > > >    void mtk_vcodec_release_dec_pm(struct mtk_vcodec_dev *dev)
> > > >    {
> > > >    	pm_runtime_disable(dev->pm.dev);
> > > > -	put_device(dev->pm.larbvdec);
> > > >    }
> > > 
> > > Now that functions only do  'pm_runtime_disable(dev->pm.dev);' so
> > > it
> > > will be more
> > > readable to remove the function mtk_vcodec_release_dec_pm
> > > and replace with pm_runtime_disable(dev->pm.dev);
> > > Same for the 'enc' equivalent.
> > 
> > Make sense. But It may be not proper if using pm_runtime_disable
> > as the symmetry with mtk_vcodec_init_dec_pm in the
> > mtk_vcodec_probe.
> > 
> > Maybe we should move pm_runtime_enable out from
> > mtk_vcodec_init_dec_pm
> > into mtk_vcodec_probe. I could do a new patch for this. Is this ok
> > for
> > you?
> 
> yes, there is also asymettry when calling pm_runtime* in general,
> I see in the decoder it is called from mtk_vcodec_dec_pm.c
> but in the encoder it is called from mtk_vcodec_enc.c,
> 
> I think all calls to pm_runtime* should be out of the *_pm.c files

OK. I will try this.

> since for example 'mtk_vcodec_dec_pw_on' also do just one call to
> pm_runtime_resume_and_get so this function can also be removed.

I guess this one should be reserved to vcodec guys. I see this function
is changed at [1]. Let's keep this patchset clean.

[1] 
https://patchwork.kernel.org/project/linux-mediatek/patch/20210901083215.25984-10-yunfei.dong@mediatek.com/

> 
> thanks,
> Dafna
> 
> > 
> > > 
> > > Thanks,
> > > Dafna
> > 
> > [snip]
> > _______________________________________________
> > Linux-mediatek mailing list
> > Linux-mediatek@...ts.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-mediatek
> > 

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