ktime_add_ns
if (ktime_before(timestamp, ktime_add_ns(prange->validate_timestamp,
ktime_add_ns(ktime_get(), vblank_timer->period),
hrtimer_start(&sched_data->timer, ktime_add_ns(ktime_get(),
const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \