dbus-sensors: Unit property for xyz.openbmc_project.Sensor.Value interface

[Ed Tanous]

On Wed, Sep 16, 2020 at 8:23 AM James Feist <james.feist at linux.intel.com> wrote:
>
> On 9/16/2020 6:28 AM, Andrei Kartashev wrote:
> > Hi,
> >
> > We noticed that dbus-sensors doesn't fully implement
> > xyz.openbmc_project.Sensor.Value interface: there is no Unit property
> > for all the sensors, defined by dbus-sensors.
> > I believe it was intentionally, but I still wondering what was the
> > reason?
>
> It was originally as the information seemed redundant. If the
> information is needed I'm fine with someone adding it, it just hasn't
> seemed to be a high priority.

Considering we've gone this long with no impact (considering the path
can be used to lookup the unit) I wonder if we should consider
removing unit from the sensor Value API?  It doesn't seem used.

>
> > I noticed that in intel-ipmi-oem units are determined based on object
> > paths, but that looks ugly since there is well-defined natural
> > interface for units in dbus.
> > Lack of the "Unit" property in the interface breaks some existing
> > logic.
> >

Technically the way the interfaces define it, both are valid to use to
determine the Units, and both would need to be lookup tables.  Is
using the path any more ugly than using the property?