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From:   Rob Herring <robh+dt@kernel.org>
Date:   Wed, 22 Nov 2023 07:55:46 -0700
Message-ID: <CAL_JsqL_caP2Adh5ntrHb24sXOY9x=TxvCSnnSCq--rm3B0FoA@mail.gmail.com>
Subject: Re: [PATCH v2] docs: dt-bindings: add DTS Coding Style document
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc:     =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <zajec5@gmail.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
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On Wed, Nov 22, 2023 at 1:05=E2=80=AFAM Krzysztof Kozlowski
<krzysztof.kozlowski@linaro.org> wrote:
>
> On 21/11/2023 14:50, Rafa=C5=82 Mi=C5=82ecki wrote:
> >> +Order of Nodes
> >> +--------------
> >> +
> >> +1. Nodes within any bus, thus using unit addresses for children, shal=
l be
> >> +   ordered incrementally by unit address.
> >> +   Alternatively for some sub-architectures, nodes of the same type c=
an be
> >> +   grouped together (e.g. all I2C controllers one after another even =
if this
> >> +   breaks unit address ordering).
> >> +
> >> +2. Nodes without unit addresses should be ordered alpha-numerically b=
y the node
> >> +   name.  For a few types of nodes, they can be ordered by the main p=
roperty
> >> +   (e.g. pin configuration states ordered by value of "pins" property=
).
> >> +
> >> +3. When extending nodes in the board DTS via &label, the entries shou=
ld be
> >> +   ordered alpha-numerically.
> >
> > Just an idea. Would that make (more) sense to make &label-like entries
> > match order of nodes in included .dts(i)?
> >
> > Adventages:
> > 1. We keep unit address incremental order that is unlikely to change
> >
> > Disadventages:
> > 1. More difficult to verify
>
> Rob also proposed this and I believe above disadvantage here is crucial.
> If you add new SoC with board DTS you are fine. But if you add only new
> board, the order of entries look random in the diff hunk. Reviewer must
> open SoC DTSI to be able to review the patch with board DTS.
>
> If review is tricky and we do not have tool to perform it automatically,
> I am sure submissions will have disordered board DTS.

I'm certainly in favor of only (or mostly?) specifying things we can
check with tools. I don't need more to check manually...

It wouldn't be too hard to get path from labels. dtc generates that
with -@ already. So I don't buy "we don't have a tool" if a tool to
check seems feasible.

Rob