[mythtv-users] Re: Backend hang after ivtv error

John Freer john_freer at yahoo.com
Tue Aug 2 02:29:28 UTC 2005

I was working with my backend box tonight, and wanted to try out
Axel's suggestion to me from earlier in this post (thanks for the

> ivtv ships its own modules for tuning. The long term plan is to use

> the v4l ones, but if they don't work use the ones from ivtv. Use
> the alias trcik in modprobe to chose the ivtv versions of tuner.ko
> etc. 

Just in case someone else tries this with what's at-testing as of
today, it doesn't work.

With the July 05 bttv / v4l packages and the 0.3w ivtv packages
(latest up at atrpms), tuning is broken either on the bttv card or
ivtv card depending which tuner module you use.

If you use the tuner-ivtv module, the PVR-250 tuner (type 50 for me)
works but my bttv card doesn't tune (type=2).  If you use the v4l
tuner module, then the bttv tuner works, but the ivtv doesn't.

I've tried the standard options of passing the tuner type parameter
to the tuner module from the bttv and ivtv modules.  No real change.

Guess we need to wait for an updated ivtv version for them to both
coexist nicely.

Happy hunting.

On Tue, Jul 26, 2005 at 08:13:00PM -0700, John Freer wrote: 
> I've been having a fairly similar problem. Hauppauge PVR-250 and a 
> Win-TV dbx, and also an HD-2000. 
> Whenever the bttv card is recording, there's a 1 in 4 chance that
> computer will hard lock and require me pushing the reset button. 
> For me this means a hang about every two weeks. 
> I see something in the logs befor the hang about IRQ problems and 
> some OCERR lines. Nothing smoking. 
> This problem has been with me since FC2 and through a couple of 
> kernels. I was hoping the recent atrpms update to bttv would fix
> problem, but I can't prove that out since the July version of bttv 
> and v4l breaks PVR-250 tuning for me. 

> Good luck. 
> JF 
> > For users & devs: 
> > I'm using two cards in my system: A hauppauge PVR-500 and a 
> > hauppauge 
> > bt878-based card. 
> > Has anyone had any problems with: 
> > 
> > 1) ivtv giving a DMA error in the log, and then 
> > 2) mythbackend fails to record using that tuner until restarted, 
> > and 
> > 3) frontends/web stop responding and repeatedly logs "waiting for

> > thread" forever. 
> > Everything works 90% of the time. This error just comes up 
> > occasionally - more often when I'm recording 2-3 shows at once. 
> > 
> > Anyone have any suggestions to improve stability? What encoder 
> > firmware are people having luck with out there? I'm using 
> > 0x02040011 
> > and ivtv-0.3.7a. 
> > 
> > For the devs: 
> > I've tracked it down to a pthread_join() statement in tv_rec.cpp.

> > It 
> > appears that when the scheduler things the recording has
> > the 
> > backend gets stuck waiting forever for the "encoder" thread to 
> > complete, which is started with pthread_create() in the 
> > "SpawnEncoder" 
> > function (or something like that....near the top of the same
> > 
> > So I know it's an ivtv error and trust me, I'm working on trying
> > fix that as fast as I can. But for now, would it be possible for 
> > mythbackend to recover from it? Perhaps replace the
> > with a non-blocking call and timeout after waiting a few seconds?

> > Or 
> > perhaps the encoder thread can exit prematurely if it doesn't get
> > buffer from the ivtv module for awhile? 
> > 
> > Also, I just checked out the source from the subversion "fixes" 
> > branch 
> > last night and installed it today. Should I expect any better 
> > behavior from that? Or should I just roll with the 0.18.1
> > 
> > I'm not using DVB.....just a PVR-500 and bt878 card. 
> > _______________________________________________ 
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> > mythtv-dev at mythtv.org 
> > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-dev 
> > 
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Axel.Thimm at ATrpms.net 

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