正常情况下，只要插了USB线，开机后就会有ifconfig usb0接口，IP地址为192.168.43.100，不需要insmod GobiNet.ko。
如果没有usb0接口，说明模块当前所处的模式不对。这个时候即使insmod GobiNet.ko，usb0接口也不会出现。
root@rk3308b-buildroot:/# lsmod
Module Size Used by Tainted: G
aic8800_bsp 73728 0
root@rk3308b-buildroot:/# lsusb
Bus 003 Device 001: ID 1d6b:0001
Bus 002 Device 003: ID 2c7c:6005
Bus 001 Device 001: ID 1d6b:0002
Bus 002 Device 001: ID 1d6b:0002
root@rk3308b-buildroot:/# ifconfig
eth0 Link encap:Ethernet HWaddr F2:2E:FE:02:6E:60
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:39
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:60 errors:0 dropped:0 overruns:0 frame:0
TX packets:60 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:4048 (3.9 KiB) TX bytes:4048 (3.9 KiB)
root@rk3308b-buildroot:/# ifconfig usb0
ifconfig: usb0: error fetching interface information: Device not found
root@rk3308b-buildroot:/#
要想让usb0接口出现，只需发AT+QCFG="usbnet",3命令让模块切换到模式3（RNDIS模式），然后发AT+CFUN=1,1命令让模块重启。
root@rk3308b-buildroot:/root# insmod usb_wwan.ko
root@rk3308b-buildroot:/root# insmod option.ko
[ 4794.877893] usbcore: registered new interface driver option
[ 4794.878214] usbserial: USB Serial support registered for GSM modem (1-port)
[ 4794.879102] option 2-1:1.2: GSM modem (1-port) converter detected
[ 4794.880421] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB0
[ 4794.881497] option 2-1:1.3: GSM modem (1-port) converter detected
[ 4794.883058] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB1
root@rk3308b-buildroot:/root# microcom /dev/ttyUSB1
AT+QCFG="usbnet",3
OK
AT+CFUN=1,1
OK
[ 4815.536085] usb 2-1: USB disconnect, device number 3
[ 4815.539263] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
[ 4815.539742] option 2-1:1.2: device disconnected
[ 4815.545028] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1
[ 4815.545563] option 2-1:1.3: device disconnected
root@rk3308b-buildroot:/root# [ 4816.480225] usb 2-1: new high-speed USB device number 4 using ehci-platform
[ 4817.138273] usb 2-1: USB disconnect, device number 4
root@rk3308b-buildroot:/root# [ 4822.800227] usb 2-1: new high-speed USB device number 5 using ehci-platform
[ 4822.936778] rndis_host 2-1:1.0 usb0: register 'rndis_host' at usb-ff440000.usb-1, RNDIS device, c6:be:9f:e6:51:b1
[ 4822.939904] option 2-1:1.2: GSM modem (1-port) converter detected
[ 4822.941051] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB0
[ 4822.943025] option 2-1:1.3: GSM modem (1-port) converter detected
[ 4822.944221] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB1
root@rk3308b-buildroot:/root# ifconfig
eth0 Link encap:Ethernet HWaddr F2:2E:FE:02:6E:60
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:39
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:1140 errors:0 dropped:0 overruns:0 frame:0
TX packets:1140 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:68848 (67.2 KiB) TX bytes:68848 (67.2 KiB)
usb0 Link encap:Ethernet HWaddr C6:BE:9F:E6:51:B1
inet addr:192.168.43.100 Bcast:192.168.43.255 Mask:255.255.255.0
inet6 addr: fe80::9b64:572a:533b:a4f4/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:7 errors:0 dropped:0 overruns:0 frame:0
TX packets:13 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1104 (1.0 KiB) TX bytes:2698 (2.6 KiB)
root@rk3308b-buildroot:/root# lsmod
Module Size Used by Tainted: G
option 53248 0
usb_wwan 20480 1 option
aic8800_bsp 73728 0
root@rk3308b-buildroot:/root#
