[mythtv] Possible firewire node/channel bug in firewire_tester, also in mythtv?

[Nathan Blythe]

After some mucking about, I've found that firewire_tester.c sets
channel = node when doing a P2P test.  This doesn't work with my STB,
an SA 8240 HDC (which appears to be mostly compatible with the
3250/4200 way of doing things).  This STB appears on my machine, as
per plugreport, as on port 0, node 1, channel 0.  firewire_tester
attempts to talk to it on port 0, node 1, channel 1, which obviously
fails.  Editing firewire_tester.c to accept the channel as an optional
command line parameter lets me force it to use channel 0, and it gets
a great connection to the STB.

MythTV fails to talk to my STB; it can change channels no problem
(which is interesting in and of itself, as the SA boxes are
notoriously hard to change channels via FireWire, so says Google) but
it fails to get a lock.  test-mpeg2, however, works flawlessly.  This
leads me to think that MythTV is making the same mistake
firewire_tester is making; assuming channel = node when in fact it
does not in my situation.

So I guess my question is: how can I see/change the specific firewire
connection information that MythTV is using to talk to my STB?  And is
what I described actually a bug in firewire_tester?  And if so, is it
also in MythTV?

For the record, I'm running MythTV version 16838 from the
"branches/release-0-21-fixes" branch with library API version
0.21.20080304-1, as packaged in Mythbuntu.

I'm not a MythTV dev, but I'm willing to mess around with the source a
bit if necessary, so any feedback is appreciated!

- Nate