Veird power reading using ipmitool

[Milton Miller II]

On May 15, 2020 around 7:19AM in some timezone, Konstantin Klubnichkin wrote:
>Hello again!
> 
>Answering myself, may be this would help anybody else.
>So the core reason is the quantum nature of the world, in this
>particular case - how fractional number are presented in IPMI.
> 
>This is well described here:
>https://github.com/openbmc/docs/blob/master/architecture/sensor-archi
>tecture.md#how-to-best-choose-coefficients
> 
>By default the upper limit for power sensors is 3000, thus the
>discreteness of the sensor value just doesn't allow it to follow the
>"real" values read from  sysfs files.
> 
>To fix this it's necessary to add custom real limits to entity
>manager configuration file.
>In my case this looks like the following:
>========================================
>"pin_Name" : "VR_P0_PIN",
>"pin_Min": 0.0,
>"pin_Max": 252.0,
>"pout1_Name" : "VR_P0_POUT",
>"pout1_Min": 0.0,
>"pout1_Max": 230.0,
>========================================
>The value of 252 Watts is taken from the power subsystem calculation,
>it's a bit more than the maximum value the VR can transform before
>shutdown.
>The same limits are set for currents and volts, and now I have sensor
>value presentation precision that allows me to get a given VR
>efficiency.
> 
>Thank you!

Thanks for sharing your successful resolution!

milton