[linux-dvb] Understanding (widespread) TT DVB-T crash

["Edward Wildgoose" <ed@wildgooses.com>]

> >> When I say, I have no crashes, I mean ARM crashes. I do have the
> >> occassional frontend lockups where you cannot tune to any channel
anymore
> >> though. In these case you can still view the OSD or replay MPEG
streams.
> >> Just tuning stops working.

..

> > I think I am confused about arm vs other crashes.  My symptoms are that
> > tuning stops working, ie tzap stops doing anything, blank picture in
vdr,
> > nothing can be read from /dev/dvb.../ - So basically nothing is coming
out
> > of the card as far as I can tell.  I haven't tried replaying mpeg
streams,
> > but yes, OSD still works in this circumstance.
>
> So it is most likely the same problem I'm facing - but this isn't the
> crash I'm talking about. Older firmware distributed with the Linux driver
> sometimes made the ARM (the video processor/whatever AV7110) crash, so
> that that it didn't handle anything. This happened regardless of the DVB
> type (S, C or T).
> The problem that we are talking about seems to be specific to DVB-T -
> maybe specific to only this special card/tuner type.
>
> This should be checked.
>
> Anyone else seeing this tuning lockup with a DVB-T and doesn't have a
> ALPS TDLB7 tuner? (Maybe we should ask this in a seperate thread?)
>
> It might be a problem with just this extra firmware from the Windows
> driver. I'm actually thinking of getting rid of this buggy card (see the
> vertical lines on the composite out...)

OK, so it seems that I misunderstood the reason why the DVB-T card was
crashing. I *AM* seeing exactly the same problem as you, ie it is basically
a tuning failure, the rest of the card seems to still work ok.

Assuming this is what the majority of other people are seeing, perhaps at
least we could narrow down exactly which component is crashing?  Also,
perhaps those with working setups could jot down more details on their
system.  I will measure signal strength on dvbtune on my system and post
back results.

For reference my system is a dual CPU 933Mhz intel machine.  Power supply
seems to have reasonable +5v and +12v, but the -5 and -12V are quite a long
way out of tolerance according to the lm_sensors measurements anyway...
Kernel is 2.4.20 on a gentoo system

My symptoms are that after tuning to different channels (must be on
different mux streams), then the card locks up in some way.  VDR still
displays stuff on the screen, so I assume OSD is still working, but no tv
signal.  From memory tzap still appears to work quite normally, however, I
get no output from the /dev/dvb devices.  I will have to double check, but I
think the card still goes through the motions and appears to tune absolutely
fine, its just that there is no mpeg output...

To the best of my knowledge the only way to restart proper service is to
"rmmod dvb-ttpci" and then reload it.  This of course also reloads the
firmware in the card (so doesn't narrow down the problem much I guess?)

Can anyone else with these problems confirm the above symptoms are also
suggest any experiments to tie down exactly which component is failing (for
example if it is a driver related problem then this may well be fixable)

Thanks all

Ed W



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