void schedule_usleep(unsigned long us)
{
  struct fast_timer t;
  wait_queue_head_t sleep_wait;
  init_waitqueue_head(&sleep_wait);

  D1(printk("schedule_usleep(%d)\n", us));
  start_one_shot_timer(&t, wake_up_func, (unsigned long)&sleep_wait, us,
                       "usleep");
  /* Uninterruptible sleep on the fast timer. (The condition is somewhat
     redundant since the timer is what wakes us up.) */
  wait_event(sleep_wait, !fast_timer_pending(&t));

  D1(printk("done schedule_usleep(%d)\n", us));
}