[PATCH v2] of: WARN on deprecated #address-cells/#size-cells handling

[Rob Herring]

On Thu, Nov 14, 2024 at 6:59 AM Segher Boessenkool
<segher at kernel.crashing.org> wrote:
>
> On Thu, Nov 07, 2024 at 10:35:58PM +1100, Michael Ellerman wrote:
> > "Rob Herring (Arm)" <robh at kernel.org> writes:
> > > While OpenFirmware originally allowed walking parent nodes and default
> > > root values for #address-cells and #size-cells, FDT has long required
> > > explicit values. It's been a warning in dtc for the root node since the
> > > beginning (2005) and for any parent node since 2007. Of course, not all
> > > FDT uses dtc, but that should be the majority by far. The various
> > > extracted OF devicetrees I have dating back to the 1990s (various
> > > PowerMac, OLPC, PASemi Nemo) all have explicit root node properties.
> >
> > I have various old device trees that have been given to me over the
> > years, and as far as I can tell they all have these properties (some of
> > them are partial trees so it's hard to be 100% sure).
>
> Many SUN systems won't have such superfluous properties.  But does
> anyone use such systems at all anymore, and do people use dtc with
> those :-)

There's still a few presumably. Sparc is omitted from this warning
already because I suspected a problem which was confirmed on v1 thanks
to the DT dumps here[1].

Rob

[1] https://git.kernel.org/pub/scm/linux/kernel/git/davem/prtconfs.git/