HDSP 9652 MIDI IN - stuck notes

[Mark Knecht <markknecht@attbi.com>]

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Hi,
   I've had a miserable stuck note problem with Alsa MIDI for a while,
so I finally sat down this evening to try and determine where the
problem was coming from, and it appears to be the HDSP 9652 MIDI input.

   My system has two 2-port MIDI interfaces, the HDSP 9652 (Alsa MIDI
64:0 & 64:32) and a MidiSport 2x2 (Alsa MIDI 72:0 & 72:1) I am using
three external hardware synths on different ports (Alsa 64:0, 72:0 and
72:1) and additionally I ran a copy each of the Linux synths ZynAddSubFx
(Alsa 130:0) and amSynth (Alsa 128:0) at the same time. (I.e. - 5 synths
in parallel, all being driven by a single MIDI input.)

   To do the tests, I use kaconnect and aconnect to build routing in the
MIDI stack to connect a single input to all outputs, which looks like
the attachment when I attach all outputs to the MidiSport Port A input.
In this configuration I can play continually, basically overdriving the
whole system with lots of MIDI events, including controllers and sustain
pedal, and I have no problems. I can do this for at least 15 minutes
with no problem on any of the synths.

   If I then change my keyboard to drive the HDSP 9652 input 1 (Alsa
64:0) and change the connections internally to drive all of outputs, I
get stuck notes pretty much immediately. It seems a bit worse with the
sustain pedal, but does not seem to be effected at all by controllers.
It is heavily effected by the MIDI note density. If I hit only one or
two notes, I'm not likely to get it, but using the sustain pedal I can
create the problem in under a minute.

   To be sure it's the input and not the outputs (as much as I can be) I
have external synths attached to the Alsa outputs on 64:0, 72:0 and
72:1. When I get a stuck note, I seem to get it on both internal soft
synths and all three external hardware synths at the same time. For this
reason I deduce that it is the HDSP input that is not clearing out
whatever event queue that holds this stuff and somehow the note never
shuts off.

   I'll be happy to try any other tests anyone wants me to look into.

   I'd be curious to know if this is a problem on any of the other RME
products that have MIDI or whether it's specifically a HDSP 9652 issue.
Also, have any other HDSP 9652 owners seen this?

   Please let me know what I might be able to do to help further get
this solved. Knowing now that the MidiSport doesn't have a problem, I
can just use it and for me that's fine. However, for others that might
be depending on the HDSP 9652 as a primary interface this would not be
acceptable.

Thanks,
Mark



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