linux-kernel - Re: [PATCH v3] arm64: dts: mediatek: Add mt8192 power domains controller

Open Source and information security mailing list archives

Date:   Thu, 18 Feb 2021 18:31:03 +0800
From:   Weiyi Lu <weiyi.lu@...iatek.com>
To:     Matthias Brugger <matthias.bgg@...il.com>,
        Enric Balletbo Serra <eballetbo@...il.com>
CC:     Rob Herring <robh@...nel.org>,
        Nicolas Boichat <drinkcat@...omium.org>,
        srv_heupstream <srv_heupstream@...iatek.com>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@...ts.infradead.org>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v3] arm64: dts: mediatek: Add mt8192 power domains
 controller

On Mon, 2020-11-30 at 19:16 +0800, Weiyi Lu wrote:
> On Fri, 2020-11-27 at 13:42 +0100, Matthias Brugger wrote:
> > 
> > On 19/11/2020 15:13, Enric Balletbo Serra wrote:
> > > Hi Weiyi,
> > > 
> > > Missatge de Weiyi Lu <weiyi.lu@...iatek.com> del dia dj., 19 de nov.
> > > 2020 a les 14:10:
> > >>
> > >> On Thu, 2020-11-19 at 13:13 +0100, Enric Balletbo Serra wrote:
> > >>> Hi Weiyi,
> > >>>
> > >>> Thank you for the patch
> > >>>
> > >>> Missatge de Weiyi Lu <weiyi.lu@...iatek.com> del dia dj., 19 de nov.
> > >>> 2020 a les 11:48:
> > >>>>
> > >>>> Add power domains controller node for SoC mt8192
> > >>>>
> > >>>> Signed-off-by: Weiyi Lu <weiyi.lu@...iatek.com>
> > >>>> ---
> > [...]
> > >>>> +                       /* System Power Manager */
> > >>>> +                       spm: power-controller {
> > >>>> +                               compatible = "mediatek,mt8192-power-controller";
> > >>>> +                               #address-cells = <1>;
> > >>>> +                               #size-cells = <0>;
> > >>>> +                               #power-domain-cells = <1>;
> > >>>> +
> > >>>> +                               /* power domain of the SoC */
> > >>>> +                               audio@...192_POWER_DOMAIN_AUDIO {
> > >>>
> > >>> If you run the dt_bindings_check it should return some errors, as all
> > >>> these node names should be 'power-domain@'. Which is a bit annoying
> > >>> because then you will get a bunch of errors like this:
> > >>>
> > >>> [    1.969110] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>> [    1.976997] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>> [    1.984828] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>> [    1.992657] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>> [    2.000685] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>> [    2.008566] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>> [    2.016395] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>> [    2.024221] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>> [    2.032049] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>> [    2.039874] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>> [    2.047699] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>> [    2.055524] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>> [    2.063352] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>> [    2.071176] debugfs: Directory 'power-domain' with parent
> > >>> 'pm_genpd' already present!
> > >>>
> > >>> But that's another problem that should be handled in debugfs system.
> > >>>
> > >>
> > >> Indeed...so I chose to use different name in dts to avoid problems in
> > >> debugfs. It does violate the naming rules.
> > >>
> > > 
> > > But your binding will not pass (or trigger warnings) the dtb check
> > > then. Rob was clear that names should be generic. Proper fix is fix
> > > debugfs not the binding.
> > > 
> > 
> > By the way, is anybody working on this debugfs issue?
> > 
> 
> I think we can solve this problem by adding "name" to the struct
> scpsys_domain_data and use this domain_data->name as the genpd.name.
> This is very simple. But I want to know if you both like it?
> 

Hi Enric and Matthias,

May I have your opinions on how you might to fix this issue?
I'll try to give another name to each power domain in the
scpsys_domain_data and register power domain with this name like below

struct scpsys_domain_data {
 	...
+	char *name;
 };

-	pd->genpd.name = node->name;
+	pd->genpd.name = pd->data->name ?: node->name;

Does it violate the naming rules to some extent? or it's acceptable?

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

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