dbus-sensors

[Matt Spinler]

Hi James,

We're looking into using dbus-sensors(HwmonTemp and PSU) in the future,
but would need to make a few changes to fit our requirements.  Was wondering
what you'd think of the following:

1. Check if a sensor has a _fault sysfs file, and if it does and it
   is nonzero, set the Functional property on the OperationalStatus
   interface to false (and/or maybe 6 below).

2. After the 10 failed reads, instead of just setting the sensor to 0
   also make a D-Bus call to create a phosphor-logging event log and set
   the OperationalStatus sensor to false.

3. After creating this event log, make sure not to do it again until
   main power is cycled.

4. If not already supported (was unsure), be able to find an
   _input file based on a value it has in the corresponding _label file.

5. We have a case where a driver isn't loaded with power off, so somehow
   we still need the sensors to stay on D-Bus when off (and show them
   as not available).

6. Maybe add a new property to Sensor.Value on the validity
   of the value property, for when driver is unloaded or there is an
   error or the sensor reading is otherwise not valid.  We could add
  this to phosphor-hwmon at the same time.
  (I think this was mentioned on the list before).

We would definitely of course work with you on the best way to
accomplish these, and I know #6 needs more discussion on if
this is something we want to do in OpenBMC, though I thought
I remembered an earlier discussion where it was popular.

Thanks,
Matt