/var/log/message 見たらですね… Jun 25 14:04:47 hina-pc kernel: hub 2-0:1.0: port 1 disabled by hub (EMI?), re-enabling... Jun 25 14:04:47 hina-pc kernel: usb 2-1: USB disconnect, address 27 Jun 25 14:04:47 hina-pc kernel: usb 2-1: new low …