Comment 2 for bug 1802431

I pretty much fixed this in a recent revision, but I think it may still be possible to overflow sometimes. I'm not sure; it still needs more testing on a super-overpowered hot-rod host. But on almost every host I've tried so far, the new thermal code gets nearly-optimal results.

The new code is, as far as I can tell, more of a PD system instead of PID. But in my testing so far, it works way better than previous versions, and in many cases the result is almost identical to what I'd get if I drew an ideal response curve by hand. So I'm calling it good for now and may do a few more tweaks later when I get better testing hosts.