thermal: uevent/netlink with step_wise?

[Brian Norris <computersforpeace@gmail.com>]

Hi,

I'm a bit new to the thermal subsystem, but I'm trying to figure out how
best to use it. It seems quite flexible, but this flexibility means it's
not obvious what the best approach to using it should be.

Particularly, I'm looking right now at using the uevent/netlink
notification mechanism. It seems that this is only active when we use
the 'user_space' governor, meaning I can't get any user-space
notifications when using the in-kernel governor. Am I missing something,
or is this a known limitation? Is there any reason we can't enable both?
For the user-space side, I'd mostly be interested in being a consumer;
e.g., display warnings in high-temperature scenarios; although I might
also use it to trigger some user-space cooling mechanisms.

Also, can anyone point me at the best up-to-date documenation,
especially any overall design documents? Should I just be looking at
Documentation/thermal/, Documentation/devicetree/bindings/thermal/, and
example drivers?

Thanks in advance.

Brian