Hi I am using Linux-2.6.31-14 based on Ubuntu karmic. I am developing a proprietary usb driver and was doing my study . I have hit upon a problem, when i insert my driver using lsmod, i get an error *Unknown symbol usb_register_driver* *Unknown symbol usb_deregister* I have used these function in my init and exit. I searched through the Linux source code 2.6.35 and 2.6.31. I find that these routines are present but has not been used in even a single driver. My questions 1. Are these some obsolete technique of registering the drivers. If yes then what is the correct method. 2. Are there any code which i have to include before compiling the kernel itself. 3. Are these functions part of any modules which i have to insert using modprobe etc technique -- Regards, Prajosh Premdas