Re: e100 PCI bridge problem

[William Montgomery]

Krzysztof Halasa wrote:

> William Montgomery <william@xxxxxxxxxxxx> 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?

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