Hi, When i compile my device driver for kernel2.6, i got a warning as followng: Warning: "isa_io_base" [/home/oliu/pmm-mpc-k26-6437/pmm.ko] undefined! When i insmod pmm.ko, i got the message as following: # insmod pmm.ko pmm: Unknown symbol isa_io_base insmod: cannot insert `pmm.ko': Unknown symbol in module (-1): No such file or directory # I am sure the symbol "isa_io_base" is not come from my driver source code. Has anybody ever met this problem before? Regards, Oliver --------------------------------- Be a better Heartthrob. Get better relationship answers from someone who knows. Yahoo! Answers - Check it out.