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

[Herrenschmidt, Benjamin]

On Mon, 2024-12-02 at 16:55 -0600, Rob Herring wrote:
>         /* Look for this #address-cells. We have to implement the old linux
>          * trick of looking for the parent here as some device-trees rely on it
>          */
> 
> Maybe that's from some system long dropped and we don't need it
> anymore. I have no idea. That's what I'm trying to find out with this
> patch.
> 
> We also don't really have a way to distinguish OF from FDT (where we'd
> need to). It is somewhat just by arch, but PPC always passes an FDT to
> the kernel for both FDT and OF systems.

I probably wrote that :-)

The little I can remember, I think is there are many cases of old DTs
(esp. old Apple ones) missing the "empty" ranges property in some nodes
to indicate that the parent and child address spaces are identical.

I honestly don't remember the specifics, but this is something I did
hit a few times in the past.

Cheers,
Ben.