Sleep until a condition gets true
wait_event_interruptible(wq, condition);
wq
the waitqueue to wait on
condition
a C expression for the event to wait for
The process is put to sleep (TASK_INTERRUPTIBLE) 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 will return -ERESTARTSYS if it was interrupted by a signal and 0 if condition evaluated to true.