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From:   Heiko Stuebner <heiko@sntech.de>
To:     Peter Geis <pgwipeout@gmail.com>,
        Krzysztof Kozlowski <krzk@kernel.org>
Cc:     Dongjin Kim <tobetter@gmail.com>,
        devicetree <devicetree@vger.kernel.org>,
        arm-mail-list <linux-arm-kernel@lists.infradead.org>,
        "open list:ARM/Rockchip SoC..." <linux-rockchip@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] arm64: dts: rockchip: Add Hardkernel ODROID-M1 board
Date:   Sun, 17 Apr 2022 22:55:25 +0200
Message-ID: <12089439.O9o76ZdvQC@phil>
In-Reply-To: <ff0135dc-da30-18b5-f5f4-cefdb0455c6b@kernel.org>
References: <20220329094446.415219-1-tobetter@gmail.com> <CAMdYzYrCZtfDiB6O20Jtp56YQhHj3jMVhCt9aCYNLbD_xwFc3g@mail.gmail.com> <ff0135dc-da30-18b5-f5f4-cefdb0455c6b@kernel.org>
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Am Sonntag, 17. April 2022, 19:45:52 CEST schrieb Krzysztof Kozlowski:
> On 16/04/2022 14:07, Peter Geis wrote:
> 
> >>> +     dc_12v: dc-12v {
> >>
> >> Generic node name, so "regulator" or "regulator-0"
> > 
> > Unfortunately, this advice breaks the regulator-fixed driver, which it
> > seems cannot cope with a bunch of nodes all named "regulator".
> 
> What exactly cannot cope? You cannot have different device nodes with
> the same name but this is not a limitation of regulator but devicetree spec.
> 
> > Setting the regulators as regulator-0 -1 -2 leads to fun issues where
> > the regulator numbering in the kernel doesn't match the node numbers.
> 
> There are no "node numbers"... maybe you mean unit addresses? But there
> are none here.
> 
> > It also makes it more fun when additional regulators need to be added
> > and everything gets shuffled around.
> 
> Usually adding - in subsequent DTS files - means increasing the numbers
> so if you have regulator-[012] then just use regulator-[345] in other
> files. I see potential mess when you combine several DTSI files, each
> defining regulators, so in such case "some-name-regulator" (or reversed)
> is also popular approach.

so going with

	dc_12v: dc-12v-regulator {
	};

i.e. doing a some-name-regulator would be an in-spec way to go?

In this case I would definitely prefer this over doing a numbered thing.

I.e. regulator-0 can create really hard to debug issues, when you have
another accidential regulator-0 for a different regulator in there, which
then would create some sort of merged node.


Heiko

> 
> > If naming these uniquely to avoid confusion and collisions is such an
> > issue, why is it not caught by make W=1 dtbs_check?
> 
> Patches are welcome. :)
> 
> Best regards,
> Krzysztof
>