Re: [PATCH] usb: xhci: add AMD PROM21 xHCI hwmon support for temperature monitoring

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Potential linker error when USB_XHCI_PCI is built-in and HWMON is a module.
--

commit 66c564d56813f3e58d95a6491735b26bfb5eb91f
Author: Jihong Min <hurryman2212@gmail.com>

usb: xhci: add AMD PROM21 xHCI hwmon support for temperature monitoring

This patch adds hwmon temperature monitoring for AMD PROM21 xHCI controllers.
The hwmon code is built as an extension to the xHCI PCI driver and
initialized during the device probe path.

> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
> index 0a277a07cf706..da41ebc272b0f 100644
> --- a/drivers/usb/host/Kconfig
> +++ b/drivers/usb/host/Kconfig
> @@ -42,6 +42,16 @@ config USB_XHCI_PCI
>  	depends on USB_PCI
>  	default y
>  
> +config USB_XHCI_PCI_PROM21_HWMON
> +	bool "AMD PROM21 xHCI temperature sensor support"
> +	depends on USB_XHCI_PCI
> +	depends on HWMON

Can this cause a linker error if CONFIG_USB_XHCI_PCI is built-in (y) and
CONFIG_HWMON is built as a module (m)?

Since USB_XHCI_PCI_PROM21_HWMON is a bool, if its dependencies evaluate to a
module, it can still be selected as built-in (y). This would compile
xhci-prom21-hwmon.c directly into vmlinux, but the code references
devm_hwmon_device_register_with_info(), which would be exported by the
dynamically loaded hwmon module, leading to an undefined reference.

Would it be safer to restrict the dependency using something like
depends on HWMON=y || HWMON=USB_XHCI_PCI?

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260506032939.92351-1-hurryman2212@gmail.com?part=1