failing on rmmod

I'm failing rmmod lcd_module.ko ERROR: Removing 'lcd_module': Device or resource busy

lssmod give me result: lcd_module [permanent]

how do I cancel this option? I want to load my module more than one time for testing.

thank you开发者_如何学Python on advance.

*if I try to install with modprobe it wont recognize my module.

You have to implement the module_exit function in your .c file, like this:

static void __exit myexit(void) {}
module_exit(myexit);

If you haven't already done so before loading your module with insmod, then the only way to remove that module is rebooting.

Also, you can attempt to force the kernel to remove the module with rmmod -f lcd_module. Cautionary note: This can cause system failure depending on what kind of resources your module has a hold of and what state its in when you try to force the removal.