[linux-dvb] Lockups with cx2388x cards
stoth at linuxtv.org
Thu Jan 10 18:41:15 CET 2008
Peter Martin wrote:
> I have a couple of Hauppauge cards (Nova-T using the cx2388x and a Nova
> Plus, again using an cx2388x) in an industrial motherboard (an Axiomtek
> ATX6022-14G) which is causing me some grief. After a short time I am
> getting both cards locking up (no DMA) at the same time.
Does it happen with only a single card active in the system?
Have you tried the cards on other motherboards and do they operate
successfully without error?
> In order to get these cards working at all in this configuration, I have
> re-arranged the SRAM and increased the FIFO size in cx88-core.c to
> 0x4800 bytes, and disabled all the other channels (video, audio etc),
> which has cured the FIFO overflow errors I was getting ( general errors:
> 0x00000100), but the cards still lock up. The cards can run from between
> 5 seconds and 30 minutes before the lockup. I also get the lockups with
> the stock code, so I am happy that my SRAM chganges have not broken
IIRC, the fifo is pretty small (resulting in potential short latency
issues). This could be compounded with a busy DMA bus and short fifo's
both competing for the same DMA queue resource. I suspect increasing the
fifo really just masks the real DMA contension issue.
What else is happening DMA wise in your system?
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