[mythtv] [Experimental PATCH] BIG DVB PATCH V1

Stephen Williams stephen.gw at gmail.com
Thu Nov 4 10:29:18 UTC 2004

> >    SIParser: ERROR: PMap Timeout in PAT Stage!
> > I don't know how terminal this is, but could it be the reason the
> > backend becomes none responsive?
> This is a terminal issue.  It shouldn't make the backend unresponsive, but if
> you are watching livetv it tends to leave a black screen up for a while until
> the backend times out..  Of course once hte backend is on a bad channel you
> have to have it change to another channel some way other than livetv to get out
> of this situation as well..

Ok, i've got further with figuring out what's going on. It seems that
the old DVB drivers I was using (linuvtx 1.0.0) were just too flaky,
they're a complete no-go with the DVB patch. Although 1.1.1 aren't
working great either....

The 1.1.1 drviers said tuning worked, got lock, signal strength great,
etc, except no data was actually being recevied from the card. It
appears to be a problem with the driver not initialising the card
properly, maybe not loading the firmware. Loading the 1.0.0 drivers,
removing them then loading the 1.1.1 drivers seemed to get things
going. Having said that, I now appear to get occasional 'packet
currupt' and 'stream continuity errors' whilst previously I never had
any. Tuning to a channel on a different mux can also take up to ten
seconds! In short, I don't trust the DVB drivers at all now and I need
to sort these problems out first.

One thing this did tell me about MythTV is that when no data is being
recevied from the DVB card the frontend will report that it can't talk
to the backend. This can occur during startup of the frontend if the
backend is performing a redicualously long 10 second channel tune.

> The current code doesn't stop looking for the PAT even after a tuning (lock)
> failure so that message alone doesn't help much..
> Are you actually getting a lock on the transport but failing to get a PAT?

Indeed, I was failing to get any packets but it's a driver issue.

So people, I need some advice. Are the DVB drivers for the 2.6 kernel
in a better state than for the 2.4 kernel i'm currently using? I've
got what I believed to be a standard card, it's a Nova-T 909 based on
the TDA10045 chipset. If anybody has info about the relative stability
of the 1.1.1 drviers against the current 2.6 kernel drivers please
drop me an email directly, there's no point pulling this thread
further OT.


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