USB to Ethernet adapter

How-to use USB to Ethernet adapters

Tested hardware

LAN JP208 (ASIX AX88772C)

LAN JP208 is a noname USB2 to Ethernet controller adapter.

On host x86 computer, this converter is identified as an ASIX 8877 chip :

[  +0,112941] usb 1-3.1.4: New USB device found, idVendor=0b95, idProduct=772b
[  +0,000003] usb 1-3.1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  +0,000002] usb 1-3.1.4: Product: AX88772C
[  +0,000002] usb 1-3.1.4: Manufacturer: ASIX Elec. Corp.
[  +0,000001] usb 1-3.1.4: SerialNumber: 00000A

Kernel configuration

The driver is included in linux menuconfig.

$ make linux-menuconfig

 Device Drivers  --->
    [*] Network device support  --->
        USB Network Adapters  --->
            [...]
            <*>   Multi-purpose USB Networking Framework
            <*>     ASIX AX88xxx Based USB 2.0 Ethernet Adapters
            [...]

Usage

Usage are the same has SMSC described below, except that:

• interface is named ethx (If you already mount the base ethernet, this adapter will be named eth1).
• The Linux configuration given here avoid modprobe.

SMSC LAN9500

The SMSC LAN9500 is a Hi-Speed USB 2.0 to 10/100 Ethernet Controller. The datasheet can be found here: http://www.smsc.com/media/Downloads_Public/Data_Sheets/9500.pdf. An external EEPROM is used to store the LAN9500 configuration.

Kernel configuration

$ make linux-menuconfig

 Device Drivers  --->
    [*] Network device support  --->
        USB Network Adapters  --->
            [...]
            <M> Multi-purpose USB Networking Framework
            [...]
            <M> CDC Ethernet support
            [...]
            <M> SMSC LAN95XX based USB 2.0 10/100 ethernet devices

Additional tools

In order to read/write the configuration eeprom of the LAN9500, Ethtool has to be used.

$ make menuconfig

Target packages  --->
    Networking applications  --->
            [*] ethtool
            [*]   enable pretty printing
             

Usage

First mount the module:

# modprobe smsc95xx

then start the new ethernet port

# ifconfig usb0 192.168.10.208 up

If the message "No EEPROM present" is displayed, this indicates that no configuration file has been detected in the EEPROM. The LAN9500 will start in a default mode and the MAC address will be randomly generated by Linux. The EEPROM can be read/write by using ethtool once the module loaded

 ethtool -e usb0   # (eeprom read)
 ethtool -E usb0 magic 0x9500 offset xxx value xxx  # (eeprom write value at offset)

Additional informations concerning the EEPROM containt can be found on the SMSC web site.