我的 USB 端口不再正常工作。我可以使用 USB 3.0 连接外部硬盘，但我尝试了两个鼠标和多个闪存驱动器，但都无济于事，
我已经重新安装了 16-04，但还是不行。
当我关机并让机器显示发生了什么事时，我得到了这个：
[ 8.607438] [drm:intel_set_pch_fifo_underrun_reporting [1915]]*ERROR* uncleared pch fifo underrun on pch transcoder A
[ 8.607461] [drm:intel_pch_fifo_underrun_irq_handler [1915]] *ERROR* PCH transcoder A FIFO underrun
[ 8.611719] usb 3-2: device descriptor read/64, error -71
[ 8.827757] usb 3-2: device descriptor read/64, error -71
[ 9.155791] usb 3-2: device descriptor read/64, error -71
[ 9.371802] usb 3-2: device descriptor read/64, error -71
[ 9.995814] usb 3.2: device not accepting address 4, error -71
[ 10.515848] usb 3.2: device not accepting address 5, error -71
[ 10.515910] usb usb3-port2: unable to enumerate usb device