Hi, At Mon, 01 Oct 2001 17:46:03 +0200, stef wrote: > > snd-card-mtpav: > > I use the Motu Midi Express XT 8 port interface. The only multiport interface, > which is supported by alsa. If i play midi songs to more than one output port > at the same time, i sometimes get hanging or dropped notes. When this happens, > some or all output LEDs of totally unused output ports are flashing. Seems as > if the data got routed to a wrong port - or was even broadcasted to all ports. > The more midi traffic, the more often this error occurs.
The problem of mtpav has been reported repeatedly by Allan, too. There must be some weird problem about routing, but it's difficult to guess since i have no hardware.. > And if i add some more midi traffic, the sequencer queue slows down. I > couldn't > believe this when i heard this slowdown first, but i measured it with > gettimeofday and snd_seq_get_queue_status and with a manual beat counter. > For example, playing 5 identical techno songs (only note events) to 5 > different interface ports results in a drop from 140bpm to 129bpm, depending > on the current midi traffic load in the song. _Very_ strange! > And, yes, i queue the events with their absolute tick times. > > Is it possible that a bug in the hw driver can slow down the queue? I mean, > playing does not pause for short times, and then goes on at 140bpm. The speed > slowly goes down from 140 to 129 as the songs get more complex. Hmm.. it's very strange, and not intended at all.. Do you mean that the calculated value is actually slow down or the actually playing tempo is slow down? So far the maximum number of events delivered at each interrupt is limited to 50. This might be the reason. This restriction is not applied in the trigger by non-interrupt call. I think RTC timer driver should work better because it uses tasklet inside. Anyway, i'll test it too (after (or during) debugging of nasty lock-up on my 2.4.10 system.. :-<) ciao, Takashi _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
