> 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
>
_______________________________________________
ivtv-users mailing list
[email protected]
http://ivtvdriver.org/mailman/listinfo/ivtv-users
