The common solution to support bind/unbind the hwmon driver base on the host state.

[Joseph Reynolds]

On 3/30/21 9:14 PM, Thu Nguyen OS wrote:
> Hi All, Currently, In Mtjade platform of Ampere, we have SMPro mdf 
> drivers (SMPro hwmon, SMPro errmon, SMPro misc driver). The drivers 
> will be loaded by kernel when the BMC boot up. But they are only 
> binded when the host is already On. ‍ ‍ ‍ ‍ 
>
> Hi All,
>
> Currently, In Mtjade platform of Ampere, we have SMPro mdf drivers 
> (SMPro hwmon, SMPro errmon, SMPro misc driver).
>
> The drivers will be loaded by kernel when the BMC boot up. But they 
> are only binded when the host is already On.
>
> They are also unbinded when the host is Off.
>
> To support binding/unbinding the SMPro drivesr, we have one service 
> name driver-binder.
>
>  1. When the Dbus property CurrentHostState of service
>     xyz.openbmc_project.State.Host changes to “not Off”, we will bind
>     the drivers.
>  2. When the Dbus property RequestedHostTransition of service
>     xyz.openbmc_project.State.Host OR Dbus property
>     RequestedPowerTransition of xyz.openbmc_project.State.Chassis
>
> change to Off, we will unbind the drivers.
>
> The driver-binder is working as expected, it have the configuration 
> file to configure which drivers will be binded/unbinded.
>
> But that is our solution.
>
> Do we have any common solution to do that job?
>

Thu,

I don't have a solution.  But I do want to be able to bind and unbind 
drivers for the BMC-attached USB ports (as the underlying mechanism when 
the BMC admin disables the ports), so I think it would be good to have a 
common solution or understand the best practices.

Joseph

> Regards.
>
> Thu Nguyen.
>