Dear Greg KH: Thanks very much for your reply. I have tried it following your advice, and yes, while I write the dynamic ID to the new_id file of the usb serial driver, such as option, pl2303, then the driver can attact to the interfaces of our device correctly. By the way, we want to make the Linux system with older linux kernel to support our device with new PID. So we have not use the dynamic id feature of the linux kernel, but not submitting the patch. Thanks again for your help. Best regards, Franko Fang 2009-1-24 ****************************************************************************************** This email and its attachments contain confidential information from HUAWEI, which is intended only for the person or entity whose address is listed above. Any use of the information contained here in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this email in error, please notify the sender by phone or email immediately and delete it! ***************************************************************************************** -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html