Re: [PATCH v3 3/4] PCI: of: introduce of_pci_verify_node()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The check in of_pci_verify_node() falsely flags compliant CardBus and PowerPC PCIe bridges as having an invalid device_type.
--

commit 72a980b9469901bec37d04c04dd8de642179aa44
Author: Alex Elder <elder@riscstar.com>

PCI: of: introduce of_pci_verify_node()

This commit introduces a runtime check to verify PCI devicetree nodes. It
ensures that bridge devices have the "pci" device_type property and that
endpoint devices do not.

> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> index a51dff91b196d..1838a3109514c 100644
> --- a/drivers/pci/of.c
> +++ b/drivers/pci/of.c

[ ... ]

> @@ -1085,3 +1085,34 @@ int of_pci_get_equalization_presets(struct device *dev,
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(of_pci_get_equalization_presets);
> +
> +/**
> + * of_pci_verify_node - Sanity check some PCI device node properties
> + * @pdev: The PCI device whose device node is checked
[ ... ]
> +void of_pci_verify_node(struct pci_dev *pdev)
> +{
> +	struct device_node *np = pci_device_to_OF_node(pdev);
> +	bool device_is_bridge;
> +	bool device_type_pci;
> +
> +	/* Nothing to check if there's no pre-existing devicetree node */
> +	if (!np)
> +		return;
> +
> +	device_is_bridge = pci_is_bridge(pdev);
> +	device_type_pci = of_node_is_type(np, "pci");
> +
> +	/* Bridges should have device type "pci"; endpoints should not */
> +	if (device_is_bridge == device_type_pci)
> +		return;
> +
> +	dev_err(&pdev->dev, "PCI %s have \"pci\" device_type property\n",
> +		device_is_bridge ? "bridge should" : "endpoint should not");

[Severity: Medium]
Will this falsely flag compliant CardBus and PowerPC PCIe bridges as having an
invalid device type?

The check in of_pci_verify_node() expects all bridges to have a device type of
exactly "pci". However, valid PCI bridges can legitimately use "cardbus" or
"pciex" as their device_type property.

When a PCI bridge with one of these valid types is added, the following call
chain unconditionally triggers this error:

pci_bus_add_device()
  of_pci_verify_node()

This could emit a false dev_err() during boot on platforms using these
standard bridges, which might alarm users by polluting the kernel logs.

> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260901011338.1323243-1-elder@riscstar.com?part=3