Hello there.
I just wanted to call your attention to a bug report I recently filed, because I'm not sure I put it in the right place: https://bugtrack.alsa-project.org/alsa-bug/view.php?id=4606
In a nutshell, ALSA seems to be dropping or corrupting output MIDI messages (both "short" and SysEx) at random as evidenced by the devices not lighting some LEDs or changing modes (sysex) on occasion. The problem is positively affected, but not completely mitigated, by the use of a real-time kernel. aseqdump -d shows everything correctly even when the device response is incorrect.
All details are in that bug report including links to alsa-info output in the notes.
Thanks for your time. Let me know if I can provide any further information.
Sincerely, Sean M. Pappalardo "D.J. Pegasus"
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