Hi,

David Brownell wrote:

   KERNEL: assertion (!dev->deadbeaf) failed at net/core/dev.c(2544)

I think there's another bug, beyond the obvious speling erorz.  Namely,
that "deadbeaf" is only set after that BUG_TRAP, or on one error path.
The assertion prevents hotpluggable network drivers from unregistering
when the hardware goes away ... which is a regression.

actually, the assertion is triggered when someone tries to unregister a
netdevice twice, and that's also why you get

   unregister_netdevice: device /dfd74058 never was registered

From a short browsing through usb.c I don't see a similiar bug catcher

in usb_device_remove(), so have a look if the USB subsystem itself
removes a unplugged device
twice for some reason.

Stefan