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From:   Arnd Bergmann <arnd@kernel.org>
Date:   Wed, 10 Feb 2021 14:53:02 +0100
Message-ID: <CAK8P3a0ALgbhTVJ7t3XRXALs9vBM=XBvkGhNKXxB+QTepo-3AQ@mail.gmail.com>
Subject: Re: [PATCH 2/5] ARM: dts: rockchip: assign a fixed index to mmc
 devices on rv1108 boards
To:     =?UTF-8?Q?Heiko_St=C3=BCbner?= <heiko@sntech.de>
Cc:     Johan Jonker <jbx6244@gmail.com>, Rob Herring <robh+dt@kernel.org>,
        "open list:ARM/Rockchip SoC support" 
        <linux-rockchip@lists.infradead.org>,
        DTML <devicetree@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Robin Murphy <robin.murphy@arm.com>
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On Wed, Feb 10, 2021 at 11:49 AM Heiko St=C3=BCbner <heiko@sntech.de> wrote=
:
> Am Mittwoch, 10. Februar 2021, 11:34:41 CET schrieb Arnd Bergmann:
> > On Wed, Feb 10, 2021 at 12:50 AM Heiko St=C3=BCbner <heiko@sntech.de> w=
rote:
> > > Am Dienstag, 9. Februar 2021, 23:25:40 CET schrieb Arnd Bergmann:
> > Each board should have its own aliases node that describes
> > exactly which of the devices are wired up on that board, and
> > in which order. If there are connectors on the board that
> > are labeled in some form, then the aliases are meant to
> > match what is written on the board or in its documentation.
>
> Then we're at least in the clear for i2c, serial and the rest ... as thes=
e
> are numbered in the soc documentation, and all boards I've seen so
> far use these number also to identify these in schematics.

Ok, that is helpful. It would still be good to ensure that only aliases
exist for nodes that are actually enabled.

> So an i2c2 is always i2c2 even if i2c1 is not populated.
>
> And of course doing
>         i2c0 =3D &i2c2
> would definitly confuse people to no end.

I think that's just an unfortunate choice of the labels here,
it's sometimes easier to just refer to the node by the full
path instead of the label.

      Arnd