Re: [PATCH v7 01/16] device property: Add fwnode_graph_get_port_by_id()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] fwnode_graph_get_port_by_id() silently fails to find port nodes that do not contain any endpoints, breaking parity with of_graph_get_port_by_id() and limiting its intended use case.
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--- Patch [1]: [PATCH v7 01/16] device property: Add fwnode_graph_get_port_by_id() ---
commit d1b7173e906ae494c3f7042d2841d794c9508816
Author: Chen-Yu Tsai <wenst@chromium.org>

device property: Add fwnode_graph_get_port_by_id()

This commit introduces a helper to retrieve a port firmware node by its ID.
It is intended to support USB power sequencing by allowing drivers to get
references to port nodes that might describe power topology.

> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index e08eadd66f4f9..0bd45f8b01c14 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c

[ ... ]

> +struct fwnode_handle *fwnode_graph_get_port_by_id(struct fwnode_handle *fwnode,
> +						  u32 id,
> +						  unsigned long flags)
> +{
> +	struct fwnode_handle *ep;
> +
> +	ep = fwnode_graph_get_endpoint_by_id(fwnode, id, 0,
> +					     flags | FWNODE_GRAPH_ENDPOINT_NEXT);
> +	if (!ep)
> +		return NULL;

[Severity: High]
Will this silently fail to find valid port nodes if they don't contain any
endpoints?

The underlying graph iteration (e.g. of_graph_get_next_endpoint())
intentionally skips port nodes that do not contain any endpoint subnodes.
If a device has a port subnode used solely for power topology (like a
vbus-supply property) without any endpoints, fwnode_graph_get_endpoint_by_id()
would return NULL here.

Does this limit the intended use case for USB power sequencing, where ports
might only contain power properties but no endpoints, and break parity with
of_graph_get_port_by_id()?

> +
> +	return fwnode_get_next_parent(ep);
> +}
> +EXPORT_SYMBOL_GPL(fwnode_graph_get_port_by_id);

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Sashiko AI review · https://sashiko.dev/#/patchset/20260724084328.3943997-1-wenst@chromium.org?part=1