运行 Ubuntu 16:04。我买了一个串行设备（ttl）到 USB，名为 cp210x。它大部分时间都正常工作，但过一段时间就会突然断开连接。有两种方法可以再次激活它，一种是重新启动 ubuntu，另一种是尝试不同的 USB 端口。后者有时才有效。
运行以下命令
dmesg | egrep --color‘serial|’
输出类似以下内容：
[ 1618.701835] usb 1-1: new full-speed USB device number 6 using xhci_hcd
[ 1619.033496] usb 1-1: New USB device found, idVendor=10c4, idProduct=ea60
[ 1619.033499] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 1619.033501] usb 1-1: Product: CP2102 USB to UART Bridge Controller
[ 1619.033503] usb 1-1: Manufacturer: Silicon Labs
[ 1619.033504] usb 1-1: SerialNumber: 0001
[ 1620.073501] usbcore: registered new interface driver usbserial
[ 1620.073511] usbcore: registered new interface driver usbserial_generic
[ 1620.073519] usbserial: USB Serial support registered for generic
[ 1620.074985] usbcore: registered new interface driver cp210x
[ 1620.074994] usbserial: USB Serial support registered for cp210x
[ 1620.075022] cp210x 1-1:1.0: cp210x converter detected
[ 1620.089846] usb 1-1: cp210x converter now attached to ttyUSB0
[ 4864.852078] cp210x ttyUSB0: failed to get comm status: -110
[ 4869.971623] cp210x ttyUSB0: failed set request 0x7 status: -110
[ 4875.095122] cp210x ttyUSB0: failed set request 0x12 status: -110
[ 4880.214602] cp210x ttyUSB0: failed set request 0x0 status: -110
[ 4892.497449] cp210x ttyUSB0: failed set request 0x0 status: -110
[ 4892.497454] cp210x ttyUSB0: cp210x_open - Unable to enable UART
[ 4897.616984] cp210x ttyUSB0: failed set request 0x0 status: -110
[ 4897.616989] cp210x ttyUSB0: cp210x_open - Unable to enable UART
[ 4905.088772] usb 1-1: USB disconnect, device number 6
[ 4905.088926] cp210x ttyUSB0: cp210x converter now disconnected from ttyUSB0
[ 4905.088940] cp210x 1-1:1.0: device disconnected
从 1620.xxx 到 4864.xxx 似乎可以工作，但是在获取通信状态后我无法再次激活它。