[Jackaudio] MOTU UltraLite AVB modulo-8 channel hopping

Hi all, the MOTU Ultralite AVB is a great USB audio interface that has a lot of connections, in/outs and a buitlin mixer plus effects that can be controlled by a web browser. Great for Linux users. With old firmwares up to 1.3.4+558 the interface runs halfway ok on older Linux kernels. More recent firmware uses an USB endpoint with implicit feedback. That can be handled with linux-5.8-rc6. With the attached kernel patch the MOTU Ultralite AVB (older model without ESS chips) runs halfway ok with this kernel. But from time to time the output hops modulo 8 when used with jackd: system:playback_1 -> ends up at 9 in the interface system:playback_2 -> ends up at 10 in the interface I can force such a hop by changing the buffer size on the fly with jack_bufsize. I think that every little hickup on USB confuses jackd. My workaround is connecting system:playback_1,9,17 and 2,10,18 Stopping/starting jackd (1.9.12) resets everything. So I am asking myself: Can this problem be fixed in jackd or is it a problem in ALSA? Regards Holger