Re: [PATCH] dt-bindings: pci: brcmstb: Add rp1-nexus node to fix DTC warning

[Krzysztof Kozlowski <krzk@kernel.org>]

On 12/08/2025 10:50, Andrea della Porta wrote:
> The devicetree compiler is complaining as follows:
> 
> arch/arm64/boot/dts/broadcom/rp1-nexus.dtsi:3.11-14.3: Warning (unit_address_vs_reg): /axi/pcie@1000120000/rp1_nexus: node has a reg or ranges property, but no unit name
> /home/andrea/linux-torvalds/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b.dtb: pcie@1000120000: Unevaluated properties are not allowed ('rp1_nexus' was unexpected)

Please trim the paths.

> 
> Add the optional node that fix this to the DT binding.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202506041952.baJDYBT4-lkp@intel.com/
> Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
> ---
>  Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml
> index 812ef5957cfc..7d8ba920b652 100644
> --- a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml
> +++ b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml
> @@ -126,6 +126,15 @@ required:
>  allOf:
>    - $ref: /schemas/pci/pci-host-bridge.yaml#
>    - $ref: /schemas/interrupt-controller/msi-controller.yaml#
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: brcm,bcm2712-pcie
> +    then:
> +      properties:
> +        rp1_nexus:

No, you cannot document post-factum... This does not follow DTS coding
style.

Also:

Node names should be generic. See also an explanation and list of
examples (not exhaustive) in DT specification:
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

... and nodes should be anyway defined in top-level and only customized
per variant. I am surprised that DTS patch carries a reviewed tag,
because it was never checked/tested :/

> +          $ref: /schemas/misc/pci1de4,1.yaml
>    - if:
>        properties:
>          compatible:


Best regards,
Krzysztof