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

Marc MERLIN marc_mtv at merlins.org
Tue May 1 19:20:46 UTC 2012

On Tue, May 01, 2012 at 02:21:40PM -0400, Peter Bennett wrote:
> 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

Yes, I mean using an insteon appliance module the takes the power away.

> 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.

1) I don't use its program guide, so I don't care :)
2) it takes 50 seconds to be able to tune its channels after being powered
back on.
3) with whatever bundle/channels I have, I have never lost the ability to
tune channels even though the box is likely off 21H/day on average.

> 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.

I measured it, it saves 1W at best. In other words, it turns off the display
and continues to suck as much power as it used to. It's a sad joke.

> 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.

Right, I noticed that.
So I think it worked a lot better for me when I was using broadcast mode: I
did not have to reprime firewire or restart the backend, it kind of just

> 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.
Interesting. For me broadcast worked for years, it was just 98% reliable so
I thought I'd use P at P. 
Yes, I have the occasional 'No input in xxx msec' problem too.
If it's still in mythtv 0.25 (I just upgraded), I'd love the patch.

Anyway it sounds like I should go back to broadcast mode, P2P and power
resets don't seem to mix :)

If you're interested, I have somewhat elaborate scripts that check the FW
connection and reset it, and also make sure that my FW input exists on
mythbackend or restarts it if not.

Those can all be run from cron:

and my somewhat complicated ACPI S3 shutdown/restart script:

"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/  

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