Re: [PATCH 4/5] arm64: dts: qcom: monaco-evk-ifp-mezzanine: use dev for device nodes

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:

New issues:
- [Medium] Mismatch between the commit title and the patch implementation regarding the new node name.

Pre-existing issues:
- [High] Renaming the endpoint nodes from 'pcie@' to 'pci@' will not prevent them from being treated as PCI buses, because the `device_type = "pci"` property is retained.
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commit c206fa07d8c746582b6a4894fa608acb472261eb
Author: Alex Elder <elder@riscstar.com>

> arm64: dts: qcom: monaco-evk-ifp-mezzanine: use dev for device nodes

[Severity: Medium]
Does the commit title match the implementation? The title explicitly mentions
using "dev for device nodes", but the patch renames the nodes to "pci@",
not "dev@".

This patch aims to fix an issue where embedded PCIe endpoints were
incorrectly treated as PCI buses after being renamed to pcie@. It
renames the nodes to pci@ to restore previous behavior and avoid
them being mistaken for bridge nodes.

> diff --git a/arch/arm64/boot/dts/qcom/monaco-evk-ifp-mezzanine.dtso b/arch/arm64/boot/dts/qcom/monaco-evk-ifp-mezzanine.dtso
> index ca5bf0fe5ec6e..a6e57ec8a1e14 100644
> --- a/arch/arm64/boot/dts/qcom/monaco-evk-ifp-mezzanine.dtso
> +++ b/arch/arm64/boot/dts/qcom/monaco-evk-ifp-mezzanine.dtso
[ ... ]
> @@ -117,7 +117,7 @@ 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: High]
This is a pre-existing issue, but does renaming the node to "pci@" actually
prevent it from being treated as a PCI bus?

The node pci@0,0 retains the device_type = "pci" property. When the devicetree
address parser matches buses, of_bus_pci_match() in drivers/of/address.c
evaluates the type before checking the node name:

drivers/of/address.c:of_bus_pci_match() {
        ...
        return of_node_is_type(np, "pci") || of_node_is_type(np, "pciex") ||
                of_node_is_type(np, "vci") || of_node_is_type(np, "ht") ||
                of_node_is_pcie(np);
}

Because device_type = "pci" remains present in the endpoint node,
of_node_is_type() will still evaluate to true. Will this cause the node to
always be matched as a PCI bus unconditionally, rendering the rename
ineffective at restoring the default-flags bus behavior?

This same question applies to the pci@0,1 node modified later in the file.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260901172058.1512508-1-elder@riscstar.com?part=4