currently I seek for a way to unload a certain module from another kernel module.
One way i think about is usage of call_usermodehelper. So basically an userspace program is prepared doing i.e. echo 1-1 > /sys//unload I think this way is possible, yet it seems not to be the best way.
I would love it, when i would not need to go over userland. So is there such a way?
Writing to sysfs attributes in general seems to be done via 
ssize_t (*show)(struct device *dev, struct device_attribute *attr, char *buf);
but seems to be done exclusivly via userland as well. Or is their a way of assembling the struct device dev parameter?