Re: [PATCH v2] dt-bindings: serial: renesas,scif: Increase number of DMA channels to 6

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] dt-bindings: serial: missing conditional maxItems restriction for dmas
--

commit 24eddc5a7c6d95e9e9c7337b59a2dae1a4924772
Author: Geert Uytterhoeven <geert+renesas@glider.be>

dt-bindings: serial: renesas,scif: Increase number of DMA channels to 6

On R-Car X5H, SCIF serial interfaces are wired to three DMACs, hence
referring to up to six DMA channels.

> diff --git a/Documentation/devicetree/bindings/serial/renesas,scif.yaml b/Documentation/devicetree/bindings/serial/renesas,scif.yaml
> index 82f54446835e6..b465c93c8357f 100644
> --- a/Documentation/devicetree/bindings/serial/renesas,scif.yaml
> +++ b/Documentation/devicetree/bindings/serial/renesas,scif.yaml
> @@ -145,14 +145,14 @@ properties:
>  
>    dmas:
>      minItems: 2
> -    maxItems: 4
> +    maxItems: 6

[Severity: Low]
Does this global relaxation of maxItems in properties.dmas cause incomplete
validation for older hardware?

By increasing the top-level maxItems limit to 6 globally without a conditional
restriction, device trees for older generations of SoCs (Gen1 through Gen4)
that incorrectly specify 5 or 6 DMA channels will now silently pass schema
validation. Previously they would be caught as errors.

This triggers when a developer defines an invalid device tree node for an older
SoC with more than 4 DMA channels and runs make dt_binding_check.

>      description:
>        Must contain a list of pairs of references to DMA specifiers, one for
>        transmission, and one for reception.
>  
>    dma-names:
>      minItems: 2
> -    maxItems: 4
> +    maxItems: 6

[Severity: Low]
Similarly, does increasing the top-level maxItems limit in properties.dma-names
globally allow invalid device trees for older SoCs to bypass validation?

Without an if-then conditional block restricting older hardware, specifying 5
or 6 DMA channel names will silently pass schema checks for SoC generations
that only support up to 4.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/4dc02f4ff8a63c2bd41b15359828ce9befd2da2f.1790071199.git.geert+renesas@glider.be?part=1