FanPwm interface

[Lei YU]

On Fri, Nov 1, 2019 at 6:32 AM Patrick Venture <venture at google.com> wrote:
>
> On Thu, Oct 31, 2019 at 3:27 PM Derek Lin23 <dlin23 at lenovo.com> wrote:
> >
> > Hi team:
> >
> >
> >
> >           I have a question regarding of FanPwm interface on hwmon.
> >
> >           Does this interface get updated while PWM is changing in sysfs?
> >
> >           For example, if I setup a fan points to a PWM like below configuration, now, FanPwm interface does not get updated when I update PWM in sysfs, only my fan inputs (rpms) do.
> >
> >
> >
> >           Example:
> >
> >           LABEL_fan1 = "FAN0_Speed"
> >
> >           …
> >
> >           PWM_TARGET_fan1 = "1"
> >
> >
> >
> >           Is there a configuration or label which I can use so FanPwm interface would get updated when I change PWM in sysfs?
>
> Unless I'm mistaken, it's currently treated only as a Target -- so
> it's updated only via dbus calls to set it.

Exactly, it will not update if you change it directly in sysfs.
This is OK in field because a regular user should access the BMC via
Redfish/REST API/ipmi.

But for debugging purpose it does have some trouble that updating pwm
in sysfs does not reflact on D-Bus.
So patches are welcome :)