Comment # 14 on bug 1190411 from Oliver Neukum

For the record:

[   30.181496] xhci_hcd 0000:00:14.0: USB bus 2 deregistered
[   30.198306] xhci_hcd 0000:00:14.0: xHCI host controller not responding,
assume dead
[   30.198314] xhci_hcd 0000:00:14.0: remove, state 1
[   30.198322] usb usb1: USB disconnect, device number 1
[   30.198623] xhci_hcd:xhci_check_args: xHCI xhci_drop_endpoint called for
root hub
[   30.198629] xhci_hcd:xhci_check_args: xHCI xhci_check_bandwidth called for
root hub
[   30.198863] xhci_hcd:xhci_dbg_trace: xhci_hcd 0000:00:14.0: // Halt the HC
[   30.198871] xhci_hcd 0000:00:14.0: Host halt failed, -19
[   30.198876] xhci_hcd 0000:00:14.0: Host not accessible, reset failed.

The HC has already failed at that point.