Re: [PATCH v2 2/5] PCI/pwrctl: Create pwrctl devices only if at least one power supply is present

[Bjorn Helgaas]

On Fri, Oct 25, 2024 at 01:24:52PM +0530, Manivannan Sadhasivam via B4 Relay wrote:
> From: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> 
> Currently, pwrctl devices are created if the corresponding PCI nodes are
> defined in devicetree. But this is not correct, because not all PCI nodes
> defined in devicetree require pwrctl support. Pwrctl comes into picture
> only when the device requires kernel to manage its power state. This can
> be determined using the power supply properties present in the devicetree
> node of the device.

> +bool of_pci_is_supply_present(struct device_node *np)
> +{
> +	struct property *prop;
> +	char *supply;
> +
> +	if (!np)
> +		return false;

Why do we need to test !np here?  It should always be non-NULL.

> +	for_each_property_of_node(np, prop) {
> +		supply = strrchr(prop->name, '-');
> +		if (supply && !strcmp(supply, "-supply"))
> +			return true;
> +	}
> +
> +	return false;
> +}