The specs sya that when the receive queue fills up with too many events, the event notifications is suspended. That's fine. But what happens afterwards, when the application has processed the backlog in the queue?
The standard doesn't appear to say that event notification will ever be re-activated. Looking at the code seems to confirm this. Once events are suspended, they will remain suspended forever.
That doesn't sound very desirable to me. Surely it should be allowable for a device to recommence events once there is space for them.