Re: [PATCH v3 2/2] arm64: dts: broadcom: bcm2712-d-rpi-5-b: add compatible

[Krzysztof Kozlowski]

On Wed, Aug 05, 2026 at 02:52:44PM +0200, Gregor Herburger wrote:
> Hi Stefan,
> On Wed, Aug 05, 2026 at 01:55:50PM +0200, Stefan Wahren wrote:
> > Hi Gregor,
> > 
> > drop Eric and add Peter.
> > 
> > Am 05.08.26 um 09:27 schrieb Gregor Herburger:
> > > On Tue, Aug 04, 2026 at 04:57:09PM +0200, Stefan Wahren wrote:
> > > > Hi Gregor,
> > > > 
> > > > sorry for my late reply.
> > > > 
> > > > Am 04.08.26 um 15:13 schrieb Gregor Herburger:
> > > > > The bcm2712 found on the Raspberry Pi 5 is available in the d Stepping
> > > > > and in a c Stepping. There are two separate dts files. The
> > > > > bcm2712-rpi-5-b.dts for the c Stepping and the bcm2712-d-rpi-5-b.dts for
> > > > > the d Stepping. The d stepping does not set its own compatible/model
> > > > > string but uses "raspberrypi,5-model-b".
> > > > In case the SoC and not the board has a D stepping, why do just change the
> > > > board compatible without the SoC compatible like "brcm,bcm2712-d0"?
> > > You mean changing both compatible strings? Like this:
> > > 	compatible = "raspberrypi,5-model-b-d0", "brcm,bcm2712-d0";
> > I just want to mention that your explanation doesn't match to your changes.
> > The first compatible represent the whole board (RPi 5) and the second one
> > represent only the SoC (BCM2712). Since the SoC is different according your
> > explanation, i would expect the SoC compatible needs to be changed. And in
> > case the SoC changes, also the board won't be compatible anymore, correct?
> Yes the SoC differs in these two versions and the board is maybe the same (but

Different SoC means different SoC-compatible. If the soc is soldered to
the board, then it also means board is different. Otherwise how can it
be the same board if it comes with different elements?

Of course boards can share schematics and everything except some
component so you could have common compatible.

1. Rpi 5b d0
2. Rpi 5b
3. bcm2712-d0

> not compatible). Compatible strings should go from most specific to most general
> [0]. If we would have the same first string for both steppings it wouldn't be
> distinguishable. So at least the first string must be unique.
> 
> E.g systemd-boot only matches the first compatible string [1].


If systemd-boot is not following established for 10 years DT practices
that systemd-boot's fault, not something to be fixed in DT.

But anyway I did not hear anyone adding/using wrong or fake compatibles
to satisfy systemd-boot for other hardware.

Best regards,
Krzysztof