interrupt problem

[Tom Appermont <tea@sonycom.com>]

Howdy,

I named the subject "interrupt problem", although I am not
completely sure it is really a problem with interrupts I'm 
having. Anyway, the symptoms are the following:

- a ddb 5074 board with 3com boomerang ethernet pci card, boots   
  with initial ramdisk (ok)
- serial interrupts work (ok)
- ethernet card interrupts work when doing a "simple" ping
- flooding the card with network packets (ping -f) causes the 
  ddb board to hang/freeze/stall after an unpredictible amount of
  time, without producing any output on the serial console.
- the problem does not seem to exist when I use a realtek ethernet
  card (ne2k driver) in stead of the 3com card.

I've tried to remedy this by:
- replacing the low level interrupt handling code for ddb5074
  with the new irq.c and time.c in arch/mips/kernel (needs 
  CONFIG_NEW_TIME_C and CONFIG_NEW_IRQ). 
- replacing the timer interrupts with CPU timer interrupts. 
- getting the newest 3c59x driver (although I don't have any
  probs with this driver on pc).
- banging my head on the table.

No luck so far. I am a bit out of ideas on how to track down the 
cause of this problem, so it would be really helpful if somebody 
could either indicate a hint of a possible solution, or suggest
ways to debug this situation.

Greetz,

Tom