Subject: Re: Recent VME spurrious interupts...
To: David Gilbert <dgilbert@jaywon.pci.on.ca>
From: Aaron Brown <abrown@eecs.harvard.edu>
List: port-sparc
Date: 03/17/1996 20:37:14
On Sun, 17 Mar 1996, David Gilbert wrote:

> 	Recently, as I mentioned before, with the installation of the
> second ethernet card in my Sun4/260 (mainly because the first wasn't
> working), I have got a lot of 'stray interrupt ipl 5' messages.  The
> ie1 card does inhabit that interupt... and the errors are related
> to activity on the ethernet.

I've been having the *exact* same problem with the le interface on the 
Sparc/Sun4m port. I've spent countless hours trying to debug it since I 
thought it was a Sun4m specific problem...perhaps it is indicative of 
something more serious in shared code.

Does everything behave fine until there is heavy traffic? If so, it 
sounds like the same problem. My current best theory is that two 
interrupts come almost at once (i.e. a transmit and a receive interrupt); 
the driver notices both and services them at once, but locore delivers 
both interrupts anyway, so the second interrupt looks like a stray.

If this is the case, I have no idea why it would show up on both a 4/260 
and an SS20...if anyone out there has ideas please feel free to share, as 
I would love to kick this bug!

--Aaron

--
Aaron B. Brown
abrown@eecs.harvard.edu