Re: [PATCH v2 4/5] iio: magnetometer: ak8975: Drop deprecated enums from OF table

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Andy,

CC devicetree

On Fri, Aug 18, 2023 at 5:03 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> On Fri, Aug 18, 2023 at 11:40:37AM +0000, Biju Das wrote:
> > > Subject: Re: [PATCH v2 4/5] iio: magnetometer: ak8975: Drop deprecated
> > > enums from OF table
> > >
> > > On Fri, Aug 18, 2023 at 08:55:59AM +0100, Biju Das wrote:
> > > > Drop deprecated enums from OF table as corresponding entries are
> > > > removed from bindings and it also saves memory.
> > >
> > > You can't do this.
> > >
> > > Only sorting by "prefixed first" criteria is possible.
> >
> > The rule applies only for fallback compatible. I checked bindings and I don't
> > find any fallback compatibles. All compatibles are just enums. Am I missing
> > anything here??
>
> Yes. As per above patch. The _whole_ world is not under your / our control.
> NAK to this change, sorry.

The single user ever in the upstream kernel was fixed in commit
9846210b1ec9bbaa ("ARM: tegra: seaboard: add missing DT vendor
prefixes") in v3.8 back in 2012.
And it had to be fixed again 9 years later in commit fa0fdb78cb5d4cde
("ARM: dts: am335x: Use correct vendor prefix for Asahi Kasei Corp.").

There may be other out-of-tree users, which would be broken by this
change.  Typically we wait a few years between deprecating a compatible
value and removing support from the driver.

As Biju is only deprecating these compatible values in PATCH 3/5 of
his series, this may be a bit premature.

Gr{oetje,eeting}s,

                        Geert


--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds