Re: [PATCH v2] arm64: dts: broadcom: bcm2712: rpi-5: Add ethernet0 alias

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Rob,

On Thu, Dec 11, 2025 at 12:42:40PM -0600, Rob Herring wrote:
> On Sun, Nov 2, 2025 at 5:15 AM Laurent Pinchart wrote:
> >
> > The RP1 ethernet controller DT node contains a local-mac-address
> > property to pass the MAC address from the boot loader to the kernel. The
> > boot loader does not fill the MAC address as the ethernet0 alias is
> > missing. Add it.
> 
> My change here[1] is going to effectively revert this.

:-(

> The RP1 stuff
> needs to either be an overlay or not. We don't need both ways.
> /aliases don't work for overlays. I suppose that could be added as a
> fixup when applying. The kernel also assumes aliases are not dynamic
> and uses indexes which aren't present, so even if it did work there
> would still be problems. OTOH, if the bootloader might use the
> ethernet controller, then why would this ever be an overlay in the
> first place?
> 
> Turns out digging into RP1 stuff, it is a mess and needs reworking[2].

I don't have a strong opinion personally. As far as I understand from
https://lore.kernel.org/all/cover.1748526284.git.andrea.porta@suse.com/,
non-overlay support was added for compatibility with downstream. I don't
know why the overlay option was considered better for upstream. Andrea,
could you comment on this ?

> Right now, I just want the warning gone so I don't get further complaints[3].
> 
> Rob
> 
> [1] https://lore.kernel.org/all/20251117211503.728354-2-robh@kernel.org/
> [2] https://lore.kernel.org/all/CAL_JsqJUzB71QdMcxJtNZ7raoPcK+SfTh7EVzGmk=syo8xLKQw@mail.gmail.com/
> [3] https://lore.kernel.org/all/CAHk-=wi+ge-gtCg+iLd6dgjisGchjtsKY8AXG9tXGOxqVv8Fkw@mail.gmail.com/

-- 
Regards,

Laurent Pinchart