Thunderbolt devices (storage, docks, hotplug)

How it tests

Watches the Thunderbolt bus and PCI devices. A newly plugged device (or one unplugged and replugged) must be authorized (“Let it in” writes authorized=1, as boltctl would) and bring up a PCI device behind it. With a port map, each Thunderbolt port is asked for in turn. When the run's own connection goes through the device (a Thunderbolt Ethernet adapter), the result waits up to 30 s for the network to come back through it, as the status line has it.

How it decides

Supported: authorized and a new non-bridge PCI device; with several ports, every port. Partial: stays unauthorized, only bridges, didn't come back after a replug, or only some ports. Failed: nothing appears on the bus (“Nothing shows up”, after 15 s).

How sure it is

It checks the whole chain, from the Thunderbolt tunnel to the device behind it.

On a real Mac

• On a MacBook Air (13-inch, Mid 2012): the Thunderbolt to Gigabit Ethernet adapter, tg3 behind two bridges.

What could mislead it

• Could pass when it shouldn'tThe PCI device appears but its driver doesn't bind or work (a driver isn't required).