Sorry for top-posting ..

I just wanted to publicly say thank you to Hans for his hard work.  The
combination of IVTV and MythTV is unbeatable.

Preet

PS No I did not change anything else.  If I did, it would not matter
because I use Axel's packages and don't roll anything myself.

On Thu, 2006-17-08 at 00:21 +0200, Hans Verkuil wrote:
> > I have been watching this thread with great interest.  Here are the
> > things that I noticed.
> >
> > - My problems only started with the 2.6.17 kernel and ivtv 0.7.0
> 
> Was that all you upgraded, or did you also upgrade other parts, either
> hardware or software like gcc?
> 
> > - I read somewhere that this is an IRQ migration problem on SMP kernels
> > so I turned off the irqbalance service.  Stability increased since
> > failures when from 1 - 5 minutes to 5 - 10 days.
> > - When I switch to a UP kernel, stability increases again.
> > - Someone mentioned a memory timing issue.  I have two sets of dual
> > channel memory.  That might also be the cause.
> >
> > What this all tells me is there is an IRQ timing issue in ivtv.  I have
> > no way to prove this since I do not dive into code and am an average end
> > user using RPMS from Axel.
> 
> What is happening is that all these actions reduce the chance of DMA
> errors. But a DMA error itself isn't a problem as there are many reasons
> why that can happen. The driver retries the last DMA transfer and there
> things go haywire. Basically the next DMA transfers are all transferred to
> a slightly shifted address (offset by somewhere between say 16-128 bytes).
> So after that all DMA transfers are shifted and the resulting MPEG stream
> is corrupt. However, it is extremely hard to determine where that offset
> comes from.
> 
> All this is not helped by the fact that for me it rarely happens, so it is
> next to impossible for me to test it. I do have some ideas to try and
> increase the chances of this happening which I'll try this weekend. If I
> can make it reliably fail within a few minutes, then I have a good
> starting point for further investigations.
> 
>         Hans
> 
> >
> > Does this help?  Do others have similar experiences?
> >
> > My machine is an AMD64 x2 in x86_64 mode.
> >
> > Preet
> >
> >
> > _______________________________________________
> > ivtv-users mailing list
> > [email protected]
> > http://ivtvdriver.org/mailman/listinfo/ivtv-users
> >
> 
> 
> 
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