ixgbe needs overtemp detection overhaul
82599, X540 (depending on firmware), and X550 can emit a Temperature Sensor interrupt (type Other) in the event that the operating temperature threshold is crossed.
The current ixgbe code is quite confused regarding this. What it considers to be an overtemp event is actually a fan failure event that is unique only to the 82598AT cards. 82598EB chips do not have the capability to report on actual temperature events, only fan failure events if a fan is equipped, such as on the add-on cards bearing that chip.
This bug is to straighten out this code and implement proper TS event detection and reporting on 82599/X540/X550, as well as clarify the fan failure detection on 82598AT add-on cards.