Man page 9 : init_timer_key

init_timer_key - initialize a timer

void init_timer_key(struct timer_list *  timer , unsigned int  flags , const char *  name , struct lock_class_key *  key );

timer
    the timer to be initialized

flags
    timer flags

name
    name of the timer

key
    lockdep class key of the fake lock used for tracking timer sync lock dependencies

init_timer_key must be done to a timer prior calling *any* of the other timer functions.