Re: [PATCH v5 4/7] arm64: dts: rockchip: describe PCIe RTL8125 Ethernet on CM3588-NAS

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Device Tree Topology Error: Conflicting PCI bus assignment for Root Port and its child device
--

commit 8bfbba94d98cec905dbfa4da80cf6195fd8103fa
Author: Ricardo Pardini <ricardo@pardini.net>

arm64: dts: rockchip: describe PCIe RTL8125 Ethernet on CM3588-NAS

This commit adds the fixed function node for the on-board Realtek RTL8125 NIC
and attaches an ethernet0 alias so that U-Boot can inject a MAC address.

> diff --git a/arch/arm64/boot/dts/rockchip/rk3588-friendlyelec-cm3588-nas.dts b/arch/arm64/boot/dts/rockchip/rk3588-friendlyelec-cm3588-nas.dts
> index f4c34da61c4df..96b3b245e0866 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3588-friendlyelec-cm3588-nas.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3588-friendlyelec-cm3588-nas.dts

[ ... ]

> @@ -512,6 +516,23 @@ &pcie2x1l1 {
>  	status = "okay";
>  };
>  
> +&pcie2x1l2 {
> +	/* on-board RTL8125 2.5GbE NIC */
> +	pcie@0,0 {
> +		reg = <0x400000 0 0 0 0>;
> +		#address-cells = <3>;
> +		#size-cells = <2>;
> +		ranges;
> +		device_type = "pci";
> +		bus-range = <0x40 0x4f>;

[Severity: Low]
Does this create a conflicting PCI bus assignment? The PCI-to-PCI bridge
pcie@0,0 resides on primary bus 0x40 but also claims a secondary bus of 0x40
via this bus-range declaration.

A bridge cannot have the same primary and secondary bus. Furthermore, its
downstream child device ethernet@0,0 is explicitly placed on bus 0x41 below,
which contradicts the bridge's claimed secondary bus 0x40.

While the Linux PCI subsystem typically ignores this DT property on bridges and
dynamically re-enumerates the bus topology correctly, could this cause issues
for static DT parsers like U-Boot that this patch relies on for MAC address
injection?

> +
> +		rtl_eth0: ethernet@0,0 {
> +			compatible = "pci10ec,8125";
> +			reg = <0x410000 0 0 0 0>;
> +		};
> +	};
> +};

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910-rk3588-dts-rtl-eth-describe-dt-alias-v5-0-c1b9e5f10cd6@pardini.net?part=4