"jackd -d firewire" starts and runs fine, and I can play and record. However every 10+-1 seconds, I get a "JackAudioDriver::ProcessAsync?: read error, skip cycle" with an accompanying audio hiccup. This happens even as root.
Despite the awkward IRQ setup on my Mac Mini (FireWire? is shared with a USB and the hard drive... UGH), I'm fairly certain this is not an IRQ issue, as "watch -d -n .5 cat /proc/interrupts" shows no regular activity on the IRQ. (Of course there is hard drive activity but this happens less often than the 10-second intervals and is not regular.)
Furthermore manually inducing hard drive activity does not cause more errors or skips.
Setup:
Edirol FA-66
jackd 1.9.5 (built from source)
FFADO 2.0.0 (Debian package)
libraw1394 2.0.5 (Debian package)
Linux 2.6.32 (built from Debian's source, not RT-patched)
new FireWire? stack enabled (and old one disabled)
FireWire? card is Agere Systems FW322/323 (rev 61)
Attached is a -v5 log (-v6 causes jackd to die...?) as well as /proc/interrupts.