Re: e100 PCI bridge problem

William Montgomery
2007-07-14T23:18:39Z

Krzysztof Halasa wrote:

>William Montgomery <william@opinicus.com> writes:
>
>
>
>>In an earlier post to the list I described a hard lockup condition
>>that occurs on linux kernels 2.4.22, 2.6.13, and 2.6.17 when using
>>a 4 port 10/100 fast ethernet card. The lockup is easily repeatable
>>and occurs on 2 out of 3 computers.
>>
>>Further testing has revealed that the lockup can be prevented on all
>>computers by making sure the card is installed on the primary PCI bus.
>>If the card is installed in a slot on the secondary PCI bus (behind a
>>PCI to PCI bridge) the lockup occurs.
>>
>>
>
>Does the machine #3 have a PCI slot connected to a "secondary" bus?
>Have you tried with any other machine with a secondary bus?
>
>
>
The #3 machine doesn't have a secondary bus. #1 and #2 are from 2
different vendors (#1 Advantech - #2 Axiomtek) and I havent tried any
othe machines.

>>Are there any PCI tuning registers that I can tweak to get around
>>this problem? Any changes I could make to the e100 driver to fix this?
>>
>>
>
>Could be a hardware/BIOS problem on machines #1 and #2. Could be
>a Linux bug as well, though similar configurations are known to work
>fine. I don't think it has anything to do with IRQs.
>
>Perhaps it doesn't like a bridge (on the card) behind a bridge
>(on the motherboard). I would test with another multiport card
>such as old DLink DFE-570TX (using a DEC 21150 bridge and four
>21143 Ethernet chips).
>
>I'd probably use some PCI analyzer or, at least, I'd check
>the bus state with a multimeter.
>
>
The #1 and #2 machines are known to work with an older Adaptec ANA-62044
4port NIC (tulip based) with an onboard Intel 21154 bridge chip. The
card I am having problems with uses an onboard Hint Corp HB6 Universal
PCI-PCI bridge.

I am using a PCI analyzer and it shows the bus in an idle state after
the lockup. The PCI transactions just prior to the lockup show a couple
of interrupts from the card which appear to be handled correctly.
Anything I should be looking for in particular?