usb 2.0 cdc-ncm 报错 内核版本 4.14.209
[800023.887452] cdc_ncm 1-1:1.0 usb0: 425 mbit/s downlink 425 mbit/s uplink
[800023.919445] cdc_ncm 1-1:1.0 usb0: network connection: disconnected
[800024.083669] IPv6: ADDRCONF(NETDEV_UP): usb0: link is not ready
[800025.487450] cdc_ncm 1-1:1.0 usb0: 425 mbit/s downlink 425 mbit/s uplink
[800025.519442] cdc_ncm 1-1:1.0 usb0: network connection: connected
[800025.525684] IPv6: ADDRCONF(NETDEV_CHANGE): usb0: link becomes ready
[801847.631424] cdc_ncm 1-1:1.0 usb0: 425 mbit/s downlink 425 mbit/s uplink
[801847.663404] cdc_ncm 1-1:1.0 usb0: network connection: disconnected
建议您确认下系统板供电，以及模组目前的网卡类型模式与系统是否匹配。谢谢！