SYNC_EVENTS_REQUESTED
if (channel->sync_events_state == SYNC_EVENTS_REQUESTED ||
channel->sync_events_state = SYNC_EVENTS_REQUESTED;
(void) cmpxchg(&channel->sync_events_state, SYNC_EVENTS_REQUESTED,
(void) cmpxchg(&channel->sync_events_state, SYNC_EVENTS_REQUESTED,