Fan controller broken in develop-ls-5.15.71-2.2.0

[sideeffect42]

The fan controller is broken in images built from the develop-ls-5.15.71-2.2.0 branch.

I tried to configure the amc6821's hwmon in Linux but all the values I change seem to have no effect.
Neither does adding amc6821.init=1 to the kernel cmdline.

If I add amc6821.pwminv=1 to the kernel cmdline the fans seem to be force set to the lowest setting.