[linux-dvb] Lockups with cx2388x cards
peter at naiadhome.com
peter at naiadhome.com
Fri Jan 11 11:32:53 CET 2008
Steven Toth wrote:
> 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?
Yes it does. If I start streaming from one card, it runs for a few minutes, then I get the timeout. I am then unable to start streaming from the other card after this. I will try a single card in the motherboard later.
> Have you tried the cards on other motherboards and do they operate
> successfully without error?
Both these cards work fine in other motherboards, indeed they work with up to 5 cards for extended periods.
>> 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.
Sounds plausible. Since the failure of one card affects the other card(s) then I suspect you are right and there is a common DMA problem here. Any suggestions as to how I can look for this, I am a relative newbie to debugging PC systems at this level. FWIW, the PCI bridge is a Pericom P17C 8150B.
> What else is happening DMA wise in your system?
Not a lot of other DMA activity. A bit of disk IO for logging, and and < 100Kbps for ethernet, but this is all being done on the controlling SBC anyway which is behind the Pericom bridge.
> - Steve
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