Re: [net-next 3/3] arm64: dts: renesas: r8a779g0: Add gPTP node

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Device Tree Resource Conflict due to overlapping memory, clock, and reset regions between `tsn0` and `gptp`.
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commit 225abba0fdcd1f7e4ebd535f168ba1447d871a7e
Author: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

arm64: dts: renesas: r8a779g0: Add gPTP node

The gPTP module is shared between the RAVB and RTSN Ethernet devices on
the SoC.

> diff --git a/arch/arm64/boot/dts/renesas/r8a779g0.dtsi b/arch/arm64/boot/dts/renesas/r8a779g0.dtsi
> index 82a7278836e57..758c4ca0ae5f2 100644
> --- a/arch/arm64/boot/dts/renesas/r8a779g0.dtsi
> +++ b/arch/arm64/boot/dts/renesas/r8a779g0.dtsi
> @@ -603,6 +603,15 @@ tsn0: ethernet@e6460000 {
>  			status = "disabled";
>  		};
>  
> +		gptp: gptp@e6449000 {
> +			compatible = "renesas,r8a779g0-gptp", "renesas,rcar-gen4-gptp";
> +			reg = <0 0xe6449000 0 0x500>;
> +			clocks = <&cpg CPG_MOD 2723>;
> +			power-domains = <&sysc R8A779G0_PD_ALWAYS_ON>;
> +			resets = <&cpg 2723>;

[Severity: High]
Will this introduce a regression by duplicating resources already claimed by
the existing tsn0 node?

Looking at the tsn0 node earlier in this file:

		tsn0: ethernet@e6460000 {
			compatible = "renesas,r8a779g0-ethertsn", "renesas,rcar-gen4-ethertsn";
			reg = <0 0xe6460000 0 0x7000>,
			      <0 0xe6449000 0 0x500>;
			reg-names = "tsnes", "gptp";
			interrupts = <GIC_SPI 429 IRQ_TYPE_LEVEL_HIGH>,
				     <GIC_SPI 430 IRQ_TYPE_LEVEL_HIGH>;
			interrupt-names = "tx", "rx";
			clocks = <&cpg CPG_MOD 2723>;
			power-domains = <&sysc R8A779G0_PD_ALWAYS_ON>;
			resets = <&cpg 2723>;
			status = "disabled";
		};

It appears tsn0 already claims the 0xe6449000 memory region, CPG_MOD 2723 clock,
and reset 2723.

If both drivers are enabled, will the second driver to probe fail when
requesting these overlapping resources, such as receiving -EBUSY from
devm_ioremap_resource() or request_mem_region()?

Should the overlapping resources be removed from the tsn0 node now that the
gPTP module is represented as a standalone shared node?

> +			status = "disabled";
> +		};
> +
>  		i2c0: i2c@e6500000 {

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Sashiko AI review · https://sashiko.dev/#/patchset/20260609215711.2960150-4-niklas.soderlund+renesas@ragnatech.se?part=1