https://bugs.launchpad.net/bugs/1177289 [ 25.544059] hub 2-0:1.0: connect-debounce failed, port 2 disabled [ 28.104055] hub 2-0:1.0: connect-debounce failed, port 3 disabled [ 28.556081] hub 2-0:1.0: unable to enumerate USB device on port 4 [ 31.132093] hub 2-0:1.0: connect-debounce failed, port 1 disabled [ 33.696081] hub 2-0:1.0: connect-debounce failed, port 2 disabled [ 36.256074] hub 2-0:1.0: connect-debounce failed, port 3 disabled [ 36.868097] hub 2-0:1.0: unable to enumerate USB device on port 4 [ 39.440080] hub 2-0:1.0: connect-debounce failed, port 1 disabled [ 42.000070] hub 2-0:1.0: connect-debounce failed, port 2 disabled [ 44.560057] hub 2-0:1.0: connect-debounce failed, port 3 disabled [ 44.948067] hub 2-0:1.0: unable to enumerate USB device on port 4 [ 47.524054] hub 2-0:1.0: connect-debounce failed, port 1 disabled [ 50.084061] hub 2-0:1.0: connect-debounce failed, port 2 disabled