Re: [PATCH 3/5] arm64: dts: qcom: lemans-evk-ifp-mezzanine: use pci for device nodes

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Ineffective Bug Fix / Logic Flaw: renaming nodes fails to prevent them from being parsed as PCI bridges
--

commit a26d89db10179b360a293aeb14a12f49b7daf216
Author: Alex Elder <elder@riscstar.com>

arm64: dts: qcom: lemans-evk-ifp-mezzanine: use pci for device nodes

This patch renames the PCIe endpoint nodes from "pcie@" to "pci@" in the
Lemans EVK IFP mezzanine devicetree. The goal is to prevent the devicetree
parsing code from incorrectly treating these endpoint nodes as PCI bridge
nodes.

> diff --git a/arch/arm64/boot/dts/qcom/lemans-evk-ifp-mezzanine.dtso b/arch/arm64/boot/dts/qcom/lemans-evk-ifp-mezzanine.dtso
> index 6cfa0bc1440e9..22c975628ed79 100644
> --- a/arch/arm64/boot/dts/qcom/lemans-evk-ifp-mezzanine.dtso
> +++ b/arch/arm64/boot/dts/qcom/lemans-evk-ifp-mezzanine.dtso
> @@ -271,7 +271,7 @@ pcie@3,0 {
>  			ranges;
>  			bus-range = <0x5 0xff>;
>  
> -			pcie@0,0 {
> +			pci@0,0 {
>  				reg = <0x50000 0x0 0x0 0x0 0x0>;
>  				#address-cells = <3>;
>  				#size-cells = <2>;
>  				device_type = "pci";

[Severity: Medium]
Will this rename successfully prevent the node from being matched as a PCI
bridge?

When the devicetree address parser matches the bus type, it iterates of_busses
and calls of_bus_pci_match() which checks:

of_bus_pci_match() {
    return of_node_is_type(np, "pci") || ... || of_node_is_pcie(np);
}

Since this node still retains the device_type = "pci" property,
of_node_is_type(np, "pci") will evaluate to true immediately.

Does this mean the of_node_is_pcie() check is completely bypassed, leaving the
node still incorrectly matched as a PCI bus? Should the device_type = "pci"
property be removed from these endpoint nodes instead, as required by the
devicetree specification?

>  				ranges;
>  			};
>  
> -			pcie@0,1 {
> +			pci@0,1 {
>  				reg = <0x50100 0x0 0x0 0x0 0x0>;
>  				#address-cells = <3>;
>  				#size-cells = <2>;
>  				device_type = "pci";

[Severity: Medium]
Does the same logic flaw apply to this node as well?

Because the device_type = "pci" property is also still present here, it
appears this node will also unconditionally match as a PCI bus in
of_bus_pci_match() regardless of the rename.

>  				ranges;
>  			};
>  		};

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260901172058.1512508-1-elder@riscstar.com?part=3