the scheduler doesn't get rid of Pd's global lock when it calls sys_send_dacs().
I thought that maybe sys_unlock should be called before sys_send_dacs, because thats the only place that pd waits under linux. didn't doublecheck though.
i'm trying to do a cleaner solution, since 1. waiting for the audio layer callback with open lock might produce some problem with messages to pd 2. for that time we have a very bad message passing resolution (with 1024 samples, about 20 ms)
... have to think a bit ...
cheers... tim