Re: [PATCH v23 08/13] mfd: core: Add firmware-node support to MFD cells

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Strict enforcement of `named_fwnode` aborts the entire MFD probe if the node is missing.
--

--- Patch [8]: [PATCH v23 08/13] mfd: core: Add firmware-node support to MFD cells ---
commit c957d9fd3d002c62018221b0f97f57bad5c0b519
Author: Shivendra Pratap <[email protected]>

mfd: core: Add firmware-node support to MFD cells

This commit extends struct mfd_cell with a named firmware-node field to allow
registering a child device using an explicit firmware node. It uses this as a
fallback when no firmware node is assigned by device tree, ACPI, or software
matching.

> diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
> index 7aa32b90cf1eb..ba9682ead2cad 100644
> --- a/drivers/mfd/mfd-core.c
> +++ b/drivers/mfd/mfd-core.c
[ ... ]
> @@ -224,6 +289,37 @@ static int mfd_add_device(struct device *parent, int id,
>  
>  	mfd_acpi_add_device(cell, pdev);
>  
> +	/* named_fwnode is a fallback only when no OF/ACPI match and no swnode */
> +	if (!pdev->dev.fwnode && !cell->swnode && cell->named_fwnode) {
> +		struct device_node *named_np;
> +
> +		fwnode = device_get_named_child_node(parent, cell->named_fwnode);
> +		if (!fwnode) {
> +			ret = -ENODEV;
> +			goto fail_alias;
> +		}

[Severity: High]
Will this strict enforcement cause the entire MFD parent probe to fail if an
optional child node is missing?

Unlike the permissive of_compatible match that merely warns and bypasses
missing nodes, returning -ENODEV here cascades up to mfd_add_devices(). This
causes a failure that unwinds all active child devices and blocks the parent
driver's probe.

Should a missing named firmware node be treated less strictly so it doesn't
disable unrelated MFD functions?

> +
> +		named_np = to_of_node(fwnode);
> +		if (named_np) {

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260714-arm-psci-system_reset2-vendor-reboots-v23-0-e7453c548c21@oss.qualcomm.com?part=8