I found the solution !!!!!!!!
When I do lsusb I have got this line :
Bus 001 Device 002: ID 0a46:6688 Davicom Semiconductor, Inc
So I look the dm9601.h file and I don't know why I don't find any DM9601_DEV entry with 0a46:6688 so I add this line at the end of the file :
DM9601_DEV( "USB Ethernet", 0x0a46, 0x6688, DEFAULT_GPIO_RESET )
After this modification It works !!!!