higher priority thread can interrupt lower priority
threads. What do
you gain if the soundcard can interrupt the jack thread? I believe
it does not matter.
For proper midi handling, all threads, irq and user, related to midi should
have a higher
priority than that of the jack thread(s).
Suppose a jack thread is running and your midiin device irq comes in but not
through,
because the device's irq thread has lower priority and does not get
scheduled!
Ralf