Olhe o meu primeiro comentário (nesse tópico).
iago@iago-Lenovo-G470:~$ dmesg | grep usb
[ 0.779719] usbcore: registered new interface driver usbfs
[ 0.779729] usbcore: registered new interface driver hub
[ 0.779750] usbcore: registered new device driver usb
[ 1.495661] usbcore: registered new interface driver libusual
[ 1.787360] usb 1-1: new high-speed USB device number 2 using ehci_hcd
[ 2.031232] usb 2-1: new high-speed USB device number 2 using ehci_hcd
[ 2.235220] usb 1-1.4: new high-speed USB device number 3 using ehci_hcd
[ 2.406997] usb 1-1.6: new full-speed USB device number 4 using ehci_hcd
[ 2.579047] usb 2-1.6: new high-speed USB device number 3 using ehci_hcd
[ 18.273739] input: Lenovo EasyCamera as /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.6/2-1.6:1.0/input/input6
[ 18.273806] usbcore: registered new interface driver uvcvideo
[ 18.274805] usbcore: registered new interface driver btusb
[ 18.401615] usbcore: registered new interface driver rts5139
[ 86.925662] usb 1-1.6: USB disconnect, device number 4
[ 226.787981] usb 2-1.4: new high-speed USB device number 4 using ehci_hcd
[ 226.888192] scsi7 : usb-storage 2-1.4:1.0
[ 226.888504] usbcore: registered new interface driver usb-storage