Re: [RFC PATCH] arm64: broadcom: bcm2712: Rework rp1 overlay handling

On 17/11/2025 22:15, Rob Herring (Arm) wrote:

It's a requirement that DT overlays be applied at build time in order to
validate them as overlays are not validated on their own.

Simply adding a build time target is possible, but it's also not desirable
to have targets which include the overlay contents and apply the same
overlay.

Rework the targets such that there are 2 overlays: the existing RP1 overlay
and the board specific configuration of the RP1 (bcm2712-rpi-5-b.dtso).

Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
---
The missing applying of rp1.dtbo will soon be a warning[1].

The comment in bcm2712-rpi-5-b.dts(o) needs updating or removing. The RP1
driver or userspace handling of the overlay probably needs updating to
handle the 2 overlays. IIRC, I think we can apply overlays to overlays
which may be useful here. If not, adding that to the tools should be
possible.

[1] https://lore.kernel.org/all/20251114222759.4181152-1-robh@kernel.org/ (local)
---
 arch/arm64/boot/dts/broadcom/Makefile                 | 10 ++++++++--
 ...m2712-d-rpi-5-b.dts => bcm2712-d-rpi-5-b-base.dts} |  2 +-
 .../{bcm2712-rpi-5-b.dts => bcm2712-rpi-5-b.dtso}     | 11 +++++------

So now Linus' tree has warnings. Can this be applied by anyone around
Broadcom and sent as fixes?


Best regards,
Krzysztof