Re: [PATCH v3 2/2] ARM: dts: armada: WRT3200ACM: add marvell,ignore-regulatory-hint

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [High] The device-specific property `marvell,ignore-regulatory-hint` is incorrectly placed in the global root node (`/`), lacking binding documentation and causing the quirk to erroneously apply to all `mwifiex` devices.
- [Medium] The `mwifiex` driver directly accesses the global `of_root` variable, which is undefined when `CONFIG_OF` is disabled, violating the driver model and risking linker errors.
--

--- Patch [2]: [PATCH v3 2/2] ARM: dts: armada: WRT3200ACM: add marvell,ignore-regulatory-hint ---
commit 7033e1a77e69407f0088e5cd43fbc6b4fc03d549
Author: Georgi Valkov <gvalkov@gmail.com>

ARM: dts: armada: WRT3200ACM: add marvell,ignore-regulatory-hint

This patch adds the marvell,ignore-regulatory-hint flag to the WRT3200ACM
device tree. It prevents the system from applying extreme restrictions due
to conflicts between the user-selected region and the radios' hard-coded
US region.

> diff --git a/arch/arm/boot/dts/marvell/armada-385-linksys-rango.dts b/arch/arm/boot/dts/marvell/armada-385-linksys-rango.dts
> index 4ab45f294de22..6e283e223ca4c 100644
> --- a/arch/arm/boot/dts/marvell/armada-385-linksys-rango.dts
> +++ b/arch/arm/boot/dts/marvell/armada-385-linksys-rango.dts
> @@ -14,6 +14,7 @@ / {
>  	model = "Linksys WRT3200ACM";
>  	compatible = "linksys,rango", "linksys,armada385", "marvell,armada385",
>  		     "marvell,armada380";
> +	marvell,ignore-regulatory-hint;

[Severity: High]
Does adding this device-specific property to the global root node (/) instead
of a dedicated device node cause a regression where it applies universally?

Because the driver in drivers/net/wireless/marvell/mwifiex/cfg80211.c queries
this property from the root node:

mwifiex_register_cfg80211():
                if (country_code &&
                    !of_property_read_bool(of_root,
                                           "marvell,ignore-regulatory-hint") &&
                    regulatory_hint(wiphy, country_code))

this board quirk will be broadcast globally across the system.

If a user connects a generic USB mwifiex Wi-Fi adapter to this router, it
appears the driver would incorrectly apply the board quirk to the external
adapter, potentially causing a regression in regulatory compliance by ignoring
its valid regulatory hint.

Would it be safer to use of_machine_is_compatible() for this platform quirk?

[Severity: Medium]
Will querying of_root directly in the mwifiex driver cause a compilation
regression when CONFIG_OF is disabled?

Since of_root is only defined in drivers/of/base.c, and the mwifiex driver
does not depend on CONFIG_OF, this relies entirely on the compiler's dead-code
elimination to drop the of_root symbol reference when of_property_read_bool()
expands to an inline dummy.

Relying on dead code elimination for undefined symbols can be brittle.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260807182124.41572-1-gvalkov@gmail.com?part=2