multiple interface test case

[Duncan Sands]

> > only a very few drivers do this kind of grab-a-bunch-of-other-devices
> > stuff.
> 
> I would be surprized if the problem is triggered only if you grab a
> _bunch_, and AFAICT there are quite a few drivers which grab at least
> one via usb_driver_claim_interface and then release it via
> usb_driver_release_interface, and thus should hit it too (unless there's
> something like an off-by-one error which is triggered only when you grab
> _all_ interfaces).

Well, some drivers try to claim the probed interface, presumably because
the author was confused.  Claiming will only do something if there are
several interfaces.  Anyway, you will only see this if you try to unload
the module with the device plugged in, and maybe that is not so common?

D.