Re: e100 PCI bridge problem

[William Montgomery <william@opinicus.com>]

Kok, Auke wrote:

> William Montgomery wrote:
>
> > Thanks for responding.  I am very interested to find the source of 
> > this problem.
> >
> > Kok, Auke wrote:
> >
> > > William Montgomery wrote:
> > >
> > > > 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.
> > >
> > >
> > > sounds like int-A/B/C/D routing issues
> >
> >
> > The strange thing is that all the ports on the card work fine for a 
> > few minutes, then when some condition (as yet unknown) occurs the 
> > system locks up hard.  I am currently using a PCI bus analyzer to 
> > capture bus activity just prior to the lockup to try and find out 
> > what leads up to this condition.
>
>
> are you running any form of irqbalance, either in-kernel (bad) or the 
> userspace (better) one?

No.  This is a Pentium 4 - single core, 2.8GHz.

> > > > 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?
> > >
> > >
> > > this issue might be resolvable by quirking the bridgee chips and 
> > > adjusting any APIC where needed. Unfortunately I don't know much 
> > > about this but it's physically not possible from the e100 driver. 
> > > The special (non-intel) card that has these 4 ports onboard contains 
> > > a bridge chip itself which explains the issues. Even a BIOS issue 
> > > could be the cause here.
> >
> >
> > I am aware of the bridge chip on the card but not sure what you mean 
> > when you say this explains the issues?  I sure would like to figure 
> > out a way around this.
>
>
> irq routing in linux may not be the same as in windows. I have no idea 
> how to compare them either (dmesg will show the linux setup, but I 
> don't know how to retreive this info under linux).

Not sure how windows applies here; I only use Linux.  The main data 
point so far is that the card works fine when on the primary PCI bus but 
locks up hard after a few minutes when installed in a slot behind a PCI 
to PCI bridge.  I can provide the dmesg info on Monday.

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