[mythtv-users] Keep losing p2p firewire connection on dch3200

[Peter Bennett]

On 4/29/2012 2:45 AM, Marc MERLIN wrote:
> I had my DCH-3200 box connected to my mythtv and mostly working in broadcast
> mode, but it would occasionally crap out.
>
> I read that peer to peer mode is more reliable so I tried to switch to that
> and got it working, but I seem to be losing the peer to peer connection
> every time the cable box is reset.
>
> So, to save power my setup is that my backend/frontend and the cable box get
> powered off when not in use.
> When mythbackend wakes back up (via RTC or because I want to watch its
> recordings), it also turns the cable box back on.
>
> With broadcast, that kind of just all worked.
>
> With P2P, it seems like the poweroff/poweron causes the p2p connection to be
> lost, and mythbackend doesn't seem to re-enable it.
>
> So, I can reprime the firewire connection, which typically gets p2p working
> again:
>
> My initscript looks like this:
>
> /usr/local/bin/firewire_tester -p -n 0 -r 5 || true
> # http://www.mythtv.org/wiki/FireWire
> plugctl -n 0 "oPCR[0].n_p2p_connections=1" || true
> plugctl -n 1 "oPCR[0].n_p2p_connections=1" || true
> sleep 3
> test -f /etc/default/locale && . /etc/default/locale 
> LANG=$LANG /usr/bin/mythbackend --syslog local7 --loglevel debug --user mythtv
>
> When I come back from sleep, though, I'm unclear as to what needs to get
> fixed and in which order.
>
> 1) do I indeed need to reprime?
> 2) looks like I need to reset the p2p bit to on
> 3) then it seems like mythbackend has lost the connection to firewire and
>    needs to be retarted, but usually if I restart it too quickly, firewire
>    isn't stable yet, and sometimes it misses the firewire recording backend.
>
> I can try adding more sleeps and kludges, but the delay becomes annoying.
>
> Is there a way to make this all work, or should I go back to broadcast?
>
> Thanks,
> Marc
When you say "powered off" do you mean actual wall power removed from
the cable box? With the soft power off by using a remote to power off
the box my firewire connection remains and nothing gets lost. On the
other hand powering off the box at the wall causes  the Comcast cable
system loses all its channels and takes several minutes to get them back
after powering on, and several days to get the program guide back.

I have a script that turns off the box via IR blaster. I have no issues
with that. The box still has power, but hopefully uses less than when it
is full on.

My experience has shown that any type of reset of the cable box,
including any disconnection of the firewire cable or power off at the
wall, needs to be followed by a restart of the back end. I have also
noticed that if the cable box gets unplugged even briefly, and replugged
it may receive a different port. The backend does not recover from this
and needs to be restarted. Also the n_p2p_connections gets reset if you
disconnect or power off the cable box at the wall.

I have always used p2p with great success, except for the "No input in
xxx msec", for which I have a patch, and with the patch my setup is
completely reliable. On my cable box, broadcast does not work at all.

If your problem is the No input in xxx msec messages, thousands of them
in the log, and recording that fails, then I have a solution that works.
Let me know.

Peter