power capping values on dbus

[Zbyszek]

wt., 26 maj 2020 o 15:01 Adrian Ambrożewicz
<adrian.ambrozewicz at linux.intel.com> napisał(a):
>
> I don't think it's clear from your message what you are trying to achieve:
> a) ability to expose power capping information as dbus-sensor just as
> read-only information
> b) ability to set the cap through D-Bus interface
>
> I suspect it's the former (just exposing data). If that's so I don't
> think you need any new interface at all. You could just add a 'Cap'
> sensor, eg Cpu0PowerCap and all the values fits nicely.

Yes, that is exactly what I want to achieve :)
Your solution sound very good, it will allow me to expose power
capping information
without any modifications to dbus-interfaces at all.
I will soon push some implementation to review under dbus-sensor.
Thanks.

>
> For latter, there already exist interface for configuring power capping
> (https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/xyz/openbmc_project/Control/Power/Cap.interface.yaml),
> however it doesn't specify properties for Min and Max values.
>
> Regards,
> Adrian
>
> W dniu 5/26/2020 o 14:46, Zbyszek pisze:
> > Hi everyone!
> >
> > I would like to expose on dbus values like min and max power capping.
> > These values could be read from files provided by hwmon like:
> >     power[1-*]_cap_max,
> >     power[1-*]_cap_min
> > which are describe here:
> > https://www.kernel.org/doc/Documentation/hwmon/sysfs-interface
> >
> > I have noticed that this interface:
> > https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/xyz/openbmc_project/Sensor/Value.interface.yaml
> > is already exposing something like MinValue and MaxValue,
> > but current implementation in dbus-sensors always sets these
> > attributes to some const values.
> > My understanding of the power capping values is that they could be used as these
> > MinValue and MaxValue if hwmon provides them otherwise some default
> > should be used as it is now.
> >
> >
> > My questions:
> > 1. Should I create a new interface for the capping readings?
> > 2. Or should I extend the existing Value.interface.yaml with new
> > attributes like MinCapValue, MaxCapValue?
> > 3  Or the correct approach would be to read the cap values if provided
> > and expose them under already existing MinValue, MaxValue?
> >
> >
> > Regards,
> > Zbigniew.
> >