Re: [PATCH] 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: schema allows 6 DMAs for older SCIF hardware
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commit ca96f7e40234020713acb3baf706d0b07d5dcc48
Author: Geert Uytterhoeven <geert@linux-m68k.org>

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

This commit updates the renesas,scif device tree binding to allow up to 6
DMA channels. This supports the R-Car X5H hardware where SCIF serial
interfaces are connected to three DMACs.

> 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 modifying the global properties.dmas limit relax the schema too much
for older hardware variants? By changing the top-level maxItems to 6, older
SCIF generations (like Gen1-Gen4) will now pass dt_binding_check even if a
device tree incorrectly specifies more than 4 DMA channels. Should this
expanded limit be constrained to the R-Car X5H compatible string using an
if-then conditional block instead?

>      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 changing the global properties.dma-names maxItems to 6
allow invalid configurations for older SoCs to pass validation? If previous
hardware only supports up to 4 DMA names, applying this limit globally
bypasses the stricter constraints of older generations.

>      items:
>        enum:
>          - tx

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Sashiko AI review · https://sashiko.dev/#/patchset/4d6e5ac045af387dde8ef3810ce08c7cb079fc29.1789653872.git.geert@linux-m68k.org?part=1