Re: [PATCH v3 1/7] dt-bindings: mailbox: Add Allwinner A523 message box

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] dt-bindings: mailbox: sun55i-a523: allwinner,tx-done-irq encodes driver policy
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commit 84f2f43ac2a1769e84ee3a5f62703aa7b08889d3
Author: Tim Michals <tcmichals@gmail.com>

dt-bindings: mailbox: Add Allwinner A523 message box

This commit adds the Devicetree binding schema for the Allwinner A523, A527,
and T527 (sun55i) message box controller, describing the four processor
register banks, clocks, resets, interrupts, and an optional
allwinner,tx-done-irq property.

> diff --git a/Documentation/devicetree/bindings/mailbox/allwinner,sun55i-a523-msgbox.yaml b/Documentation/devicetree/bindings/mailbox/allwinner,sun55i-a523-msgbox.yaml
> new file mode 100644
> index 0000000000000..47b6fe304dbc8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/allwinner,sun55i-a523-msgbox.yaml

[ ... ]

> +  interrupts:
> +    items:
> +      - description: Cortex-A55 bank read interrupt, messages for the host
> +      - description: HiFi4 DSP bank write interrupt for the host
> +      - description: CPUS bank write interrupt for the host
> +      - description: XuanTie RISC-V bank write interrupt for the host
> +
> +  interrupt-names:
> +    items:
> +      - const: arm
> +      - const: dsp
> +      - const: cpus
> +      - const: rv
> +
> +  allwinner,tx-done-irq:
> +    type: boolean
> +    description:
> +      Signal TX done with the write interrupt of the receiver's bank instead
> +      of polling. A message is done once the receiver's FIFO has room for the
> +      next one either way; the write interrupt is raised while the FIFO has
> +      room. Without this property a full FIFO is polled. Received messages
> +      use the host bank read interrupt either way.

[Severity: Medium]
Since the schema unconditionally requires all four hardware interrupt lines
(arm, dsp, cpus, and rv) in interrupts and interrupt-names, and every A523
SoC wires the three remote bank write interrupts to the GIC, this boolean
property appears to only select between interrupt-driven and polled TX
completion in the driver rather than describing a hardware difference.

Given that Devicetree bindings should describe hardware capabilities and
wiring rather than OS driver runtime policy, should allwinner,tx-done-irq be
dropped from the binding so the driver decides how to handle TX completion?

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Sashiko AI review · https://sashiko.dev/#/patchset/20261101185735.762559-1-tcmichals@gmail.com?part=1