PID control configuration usage

[Matthew Barth]

On 3/6/19 2:31 PM, Ed Tanous wrote:
> On 3/6/19 11:36 AM, Matthew Barth wrote:
>> I'm investigating the functionality and use of pid-control to what is
>> currently being used on IBM's witherspoon system.
> Sweeeeeet.
> 
>> Is there a PID control
>> configuration being used that's upstream? I am unable to find any
>> systems in the meta layers using pid-control that provides a direct
>> configuration example. It looks to be used in the Intel layer that pulls
>> a config together from entity-manager and presents it on dbus to
>> pid-control, but I dont follow how the entity-manager json transforms to
>> the consumable pid-control json.
> It doesn't.  When using the entity manager configs, the DBUS data
> structures are read directly by pid-control, and converted into the C
> data structures that the JSON would've been encoded to at build time.
> no json is created or destroyed.
> 
Thanks for clarifying that

>> Could someone point me to a functional
>> (possibly in-use) example or show the json config produced from
>> entity-manager?
> I thought the Quanta system used it, but I'm not seeing the JSON.
> Patrick checked in a basic example here:
> https://github.com/openbmc/phosphor-pid-control/blob/master/examples/fan-info.json
> But I'm guessing you already found that.
I did see that. I used that as my starting point, but its quite a simple 
config that I was interested in seeing a more complex example that's in use.

> 
> I'm not sure if it helps, but here's a dump of the entity-manager dbus
> interfaces, on a system with a dozen or so add in fru devices detected.
> Each fru device has its own thermal controllers installed and exposed to
> dbus.
> 
> https://pastebin.com/jaKw5TJa
Thanks, I'll dig thru this to see if I can associate the corresponding 
json entries I'd setup and give to swampd at startup.

Matt

> 
> -Ed
>