Man page 9 : wait_event_hrtimeout

wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses

wait_event_hrtimeout( wq , condition , timeout );

wq
    the waitqueue to wait on

condition
    a C expression for the event to wait for

timeout
    timeout, as a ktime_t

The process is put to sleep (TASK_UNINTERRUPTIBLE) until the condition evaluates to true or a signal is received. The condition is checked each time the waitqueue wq is woken up.

wake_up has to be called after changing any variable that could change the result of the wait condition.

The function returns 0 if condition became true, or -ETIME if the timeout elapsed.