Faking Sensor Readings

[James Feist]

On 12/4/19 1:39 AM, rgrs wrote:
> Hi James,
> 
> I tried busctl set-property,  but the values didn't change.
> Are the steps below correct?
> (test with both 'field mode' enabled and disabled)
> 
> root at obmc:~# busctl introspect xyz.openbmc_project.Hwmon-2439434288.Hwmon1  /xyz/openbmc_project/sensors/temperature/INLET_TEMP xyz.openbmc_project.Sensor.Value --no-pager
> NAME                             TYPE      SIGNATURE RESULT/VALUE                             FLAGS
> .MaxValue                        property  x         0                                        emits-change writable
> .MinValue                        property  x         0                                        emits-change writable
> .Scale                           property  x         -3                                       emits-change writable
> .Unit                            property  s         "xyz.openbmc_project.Sensor.Value.Unit.… emits-change writable

This looks like phosphor-hwmon, not dbus-sensors 
https://github.com/openbmc/dbus-sensors.


> .Value                           property  x         18500                                    emits-change writable
> 
> root at obmc:~# busctl --no-pager set-property xyz.openbmc_project.Hwmon-2439434288.Hwmon1  /xyz/openbmc_project/sensors/temperature/INLET_TEMP xyz.openbmc_project.Sensor.Value  Value x 50000
> 
> root at saber:~# busctl --no-pager get-property xyz.openbmc_project.Hwmon-2439434288.Hwmon1  /xyz/openbmc_project/sensors/temperature/INLET_TEMP xyz.openbmc_project.Sensor.Value  Value
> x 18500
> 
> root at obmc:~#
> 
> Thanks,
> Raj
> 
> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> On Wednesday, December 4, 2019 1:34 AM, James Feist <james.feist at linux.intel.com> wrote:
> 
> > On 12/3/19 5:49 AM, Alexander Amelkin wrote:
> >
> > > 03.12.2019 15:06, rgrs wrote:
> > >
> > > > Hi,
> > > > How do I fake sensor readings in OpenBMC?
> > > > We're trying to fake temperature sensors and make sure fans ramp up/down
> > > > accordingly.
> > >
> > > We ended up patching the kernel driver to fake the readings by request.
> > > I'm not aware of any ready interface in OpenBMC for that.
> >
> > If you're using d-bus sensors, the sensor property is writable. It is
> > also supported by patching the sensor value in redfish.
> >
> > > With best regards,
> > > Alexander Amelkin
> 
> </james.feist at linux.intel.com>
>