Re: [PATCH v2 07/11] regulator: wm831x: support software node in platform data

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Using `device_set_node()` on an already-registered platform device destructively overwrites its primary firmware node and introduces dangling pointer/use-after-free risks.
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--- Patch [7]: [PATCH v2 07/11] regulator: wm831x: support software node in platform data ---
commit 41eed35e80fd0a1bdad7b80c52433a74629a0ec0
Author: Dmitry Torokhov <dmitry.torokhov@gmail.com>

regulator: wm831x: support software node in platform data

This commit allows passing a software node via platform data to the
wm831x buckv regulators. It attempts to read DVS configuration from the
software node if it is present, falling back to legacy platform data.

> diff --git a/drivers/regulator/wm831x-dcdc.c b/drivers/regulator/wm831x-dcdc.c
> --- a/drivers/regulator/wm831x-dcdc.c
> +++ b/drivers/regulator/wm831x-dcdc.c

[ ... ]

> @@ -332,14 +333,26 @@ static void wm831x_buckv_dvs_init(struct platform_device *pdev,
>  	struct wm831x *wm831x = dcdc->wm831x;
>  	int ret;
>  	u16 ctrl;
> +	int dvs_control_src;
> +	u32 val;
>  
>  	if (!pdata)
>  		return;
>  
> +	if (pdata->swnode) {
> +		struct fwnode_handle *fwnode = software_node_fwnode(pdata->swnode);
> +
> +		if (fwnode)
> +			device_set_node(&pdev->dev, fwnode);

[Severity: High]
Does overwriting the primary firmware node here with device_set_node()
safely manage the device lifecycle?

Calling device_set_node() on an already-registered platform device destructively
overwrites its primary fwnode, clearing any Device Tree or ACPI bindings
established by the MFD core. It also bypasses the correct API for secondary
nodes (device_add_software_node()).

If a later step in wm831x_buckv_probe() fails and the driver unwinds, the
modified pdev->dev.fwnode is never restored. This leaves a dangling pointer
to the unrefcounted software node.

Should this code use device_add_software_node() instead?

> +	}
> +

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Sashiko AI review · https://sashiko.dev/#/patchset/20260708-samsung-kp-v2-0-3c6ed4c9b3b6@gmail.com?part=7