[PATCH v2 02/16] device property: Add fwnode_graph_get_next_port_endpoint()

[Andy Shevchenko]

On Wed, Jun 10, 2026 at 04:40:36PM +0800, Chen-Yu Tsai wrote:
> Due to design constraints of the power sequencing API, the consumer
> must first be sure that the other side is actually a provider, or it
> will continually get -EPROBE_DEFER when requesting the power
> sequencing descriptor.
> 
> In the upcoming USB power sequencing integration, the USB hub driver
> first needs to check whether a graph connection exists, and whether
> the other side of the connection is a supported connector type. The
> USB port is tied to a "port" firmware node, and this new helper will
> be used to get the endpoint under the known "port" firmware node.

...

> +/**
> + * fwnode_graph_get_next_port_endpoint - Get next endpoint firmware node in port
> + * @port: Pointer to the target port firmware node
> + * @prev: Previous endpoint node or %NULL to get the first
> + *
> + * The caller is responsible for calling fwnode_handle_put() on the returned
> + * fwnode pointer. Note that this function also puts a reference to @prev
> + * unconditionally.
> + *
> + * Return: an endpoint firmware node pointer or %NULL if no more endpoints
> + * are available.

Yeah, you see, even here is inconsistency with previously added kernel-doc.

> + */
> +struct fwnode_handle *fwnode_graph_get_next_port_endpoint(const struct fwnode_handle *port,
> +							  struct fwnode_handle *prev)
> +{
> +	struct fwnode_handle *ep;

Unused?

> +	while (1) {

This is usually harder to read and follow. It's like "pay much attention on
the code", but here no rocket science, no code to really pay attention to.

> +		prev = fwnode_get_next_child_node(port, prev);
> +		if (!prev)
> +			break;
> +
> +		if (WARN(!fwnode_name_eq(prev, "endpoint"),
> +			 "non endpoint node is used (%pfw)", prev))
> +			continue;
> +
> +		break;
> +	}
> +
> +	return prev;
> +}

So, this can be rewritten as

	ep = prev;
	do {
		ep = fwnode_get_next_child_node(port, ep);
		if (fwnode_name_eq(ep, "endpoint"))
			break;

		WARN_ON(ep, ...);
	} while (ep);

	return ep;

But also big question why? to WARN*(). There is no use in the entire
property.c.

-- 
With Best Regards,
Andy Shevchenko