如题，我尝试了把它在我的台式机上，操作系统为ubuntu 20.4，工作正常，我认为这说明我的AT指令配置是没有问题的？
但是在Jeston Nano平台上电时，dmesg会打印：
[ 1032.507694] usb 2-1.2: new SuperSpeed USB device number 5 using tegra-xusb
[ 1032.528696] usb 2-1.2: New USB device found, idVendor=2c7c, idProduct=0900
[ 1032.528702] usb 2-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 1032.528706] usb 2-1.2: Product: RM500U-CN
[ 1032.528709] usb 2-1.2: Manufacturer: Quectel
[ 1032.528712] usb 2-1.2: SerialNumber: 0123456789ABCDEF
[ 1032.531541] cdc_ether 2-1.2:1.0 usb0: register ‘cdc_ether’ at usb-70090000.xusb-1.2, CDC Ethernet Device, fe:77:bb:29:89:99
[ 1032.535633] option 2-1.2:1.2: GSM modem (1-port) converter detected
[ 1032.535951] usb 2-1.2: GSM modem (1-port) converter now attached to ttyUSB0
[ 1032.536183] option 2-1.2:1.3: GSM modem (1-port) converter detected
[ 1032.536354] usb 2-1.2: GSM modem (1-port) converter now attached to ttyUSB1
[ 1032.536565] option 2-1.2:1.4: GSM modem (1-port) converter detected
[ 1032.536741] usb 2-1.2: GSM modem (1-port) converter now attached to ttyUSB2
[ 1032.537127] option 2-1.2:1.5: GSM modem (1-port) converter detected
[ 1032.537440] usb 2-1.2: GSM modem (1-port) converter now attached to ttyUSB3
[ 1032.537693] option 2-1.2:1.6: GSM modem (1-port) converter detected
[ 1032.537872] usb 2-1.2: GSM modem (1-port) converter now attached to ttyUSB4
[ 1032.753946] IPv6: ADDRCONF(NETDEV_UP): usb0: link is not ready
[ 1032.804344] IPv6: ADDRCONF(NETDEV_UP): usb0: link is not ready
[ 1048.521426] IPv6: ADDRCONF(NETDEV_CHANGE): usb0: link becomes ready
[ 1098.177053] cdc_ether 2-1.2:1.0 usb0: kevent 12 may have been dropped
[ 1098.184254] cdc_ether 2-1.2:1.0 usb0: kevent 12 may have been dropped
另外AT端打印：
AT^S
RDY
+QUSIM: 1
+CPIN: READY
+QIND: PB DONE
AT^SQPORT?
+CME ERROR: 4
+CFUN: 1
+QIND: SMS DONE
AT
+QNETDEVSTATUS: 1,1,“IPV4V6”,0
AT
AT+CGMI
Quectel
OK
AT+GMIAT+CGMM
RM500U-CN
OK
AT+GMM
AT%IPSYS?
+CME ERROR: 4
AT%IPSYS?
+CME ERROR: 4
AT%IPSYS?
+CME ERROR: 4
ATE0
OK
OK
OK
+CME ERROR: 4
OK
OK
+GCAP: +GSM
OK
Quectel
RM500U-CN
Revision: RM500UCNAAR01A07M2G
OK
+CPIN: READY
OK
RM500U-CN
OK
打印的同时，ifconfig会有如下变化：
mr123@mr123-emmc3:~$ ifconfig usb0
usb0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet6 fe80::6cc:e4f2:4575:8e23 prefixlen 64 scopeid 0x20
ether fe:77:bb:29:89:99 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
mr123@mr123-emmc3:~$ ifconfig usb0
usb0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether fe:77:bb:29:89:99 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
mr123@mr123-emmc3:~$ ifconfig usb0
usb0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::6cc:e4f2:4575:8e23 prefixlen 64 scopeid 0x20
ether fe:77:bb:29:89:99 txqueuelen 1000 (Ethernet)
RX packets 2 bytes 172 (172.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 2 bytes 432 (432.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
mr123@mr123-emmc3:~$ ifconfig usb0
usb0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 100.95.21.59 netmask 255.0.0.0 broadcast 100.255.255.255
inet6 fe80::6cc:e4f2:4575:8e23 prefixlen 64 scopeid 0x20
ether fe:77:bb:29:89:99 txqueuelen 1000 (Ethernet)
RX packets 8 bytes 1624 (1.6 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 19 bytes 2747 (2.7 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
mr123@mr123-emmc3:~$ ifconfig usb0
usb0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 100.95.21.59 netmask 255.0.0.0 broadcast 100.255.255.255
inet6 fe80::6cc:e4f2:4575:8e23 prefixlen 64 scopeid 0x20
inet6 240e:473:c30:a205:5538:e80c:12f1:9846 prefixlen 64 scopeid 0x0
inet6 240e:473:c30:a205:3c16:9491:e105:3772 prefixlen 64 scopeid 0x0
ether fe:77:bb:29:89:99 txqueuelen 1000 (Ethernet)
RX packets 15 bytes 2322 (2.3 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 41 bytes 5815 (5.8 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
mr123@mr123-emmc3:~$ ifconfig usb0
usb0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether fe:77:bb:29:89:99 txqueuelen 1000 (Ethernet)
RX packets 22 bytes 3292 (3.2 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 90 bytes 13656 (13.6 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
我希望能得到一些指导，这些现象表明我的适配过程中有什么地方出问题了吗？ 在Jeston Nano平台适配RM500U-CN，网络连接失败