Re: [PATCH net-next v7 01/10] dt-bindings: net: airoha: Add EN7581 ethernet-ports properties

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] Unconditionally requiring `#address-cells` and `#size-cells` for `ethernet@3` and `ethernet@4` breaks backward compatibility and causes `dtc` warnings.
- [Low] The `reg` property in the `airoha,eth-port` node incorrectly uses `maxItems: 5` instead of `maximum: 5`.
--

commit f8c9c25c14697c9de91b47f1ea5850c1b33f44a9
Author: Lorenzo Bianconi <lorenzo@kernel.org>

dt-bindings: net: airoha: Add EN7581 ethernet-ports properties

The EN7581 and AN7583 SoCs support connecting multiple external SerDes to GDM3
or GDM4 ports via a hw arbiter that manages the traffic in a TDM manner. This
commit introduces the ethernet-port property in order to model a given
net_device connected via the external arbiter.

> diff --git a/Documentation/devicetree/bindings/net/airoha,en7581-eth.yaml b/Documentation/devicetree/bindings/net/airoha,en7581-eth.yaml
> index fbe2ddcdd909c..7144d6da7394b 100644
> --- a/Documentation/devicetree/bindings/net/airoha,en7581-eth.yaml
> +++ b/Documentation/devicetree/bindings/net/airoha,en7581-eth.yaml
> @@ -130,6 +130,46 @@ patternProperties:
>          maximum: 4
>          description: GMAC port identifier
>  
> +    allOf:
> +      - if:
> +          properties:
> +            reg:
> +              contains:
> +                items:
> +                  - enum:
> +                      - 3
> +                      - 4
> +        then:
> +          properties:
> +            '#address-cells':
> +              const: 1
> +
> +            '#size-cells':
> +              const: 0
> +
> +          patternProperties:
> +            "^ethernet@[0-5]$":
> +              type: object
> +              unevaluatedProperties: false
> +              $ref: ethernet-controller.yaml#
> +              description: External ethernet port ID available on the GDM port
> +
> +              properties:
> +                compatible:
> +                  const: airoha,eth-port
> +
> +                reg:
> +                  maxItems: 5

Could this maxItems constraint allow the reg array to contain up to 5 elements
(e.g., reg = <0 1 2 3 4>)? Since the parent node enforces #address-cells = <1>
and #size-cells = <0>, shouldn't this use maximum: 5 instead to restrict the
numeric value of a single port ID?

> +                  description: External ethernet port identifier
> +
> +              required:
> +                - reg
> +                - compatible
> +
> +          required:
> +            - "#address-cells"
> +            - "#size-cells"

Will unconditionally requiring #address-cells and #size-cells for ethernet@3
and ethernet@4 break configurations that don't use the external arbiter?

If a board connects the GDM3 or GDM4 port directly to a PHY without child nodes,
it seems these properties would fail schema validation.

Also, if added merely to satisfy dtbs_check, wouldn't dtc emit an
avoid_unnecessary_addr_size warning when the node has no children?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260516-airoha-eth-multi-serdes-v7-0-99e0093303e2@kernel.org?part=1