Re: forcing a pci nic to use a different irq?

[Paul Mackinney <pmackinney@home.com>]

Matthew Garman muttered:
> According to the Ethernet HOWTO, the most common cause of this problem is
> an IRQ conflict.  This seems believable, because...
> 
> cat /proc/interrupts
> 
>            CPU0       
>   0:      42726          XT-PIC  timer
>   1:       2024          XT-PIC  keyboard
>   2:          0          XT-PIC  cascade
>   4:      12012          XT-PIC  
>   5:          3          XT-PIC  soundblaster
>  11:       5986          XT-PIC  sym53c8xx, eth0
>  12:       4799          XT-PIC  PS/2 Mouse
>  14:          2          XT-PIC  ide0
> NMI:          0 
> ERR:          0
> 
> You can see that both my SCSI controller and my ethernet card live on IRQ
> 11.
I'm not an expert on IRQs, but my (vague!) understanding is that it's 
actually the PCI controller that uses the IRQ, so if these devices are 
on the same bus, it doesn't necessarily indicate a conflict.

Joost is absolutely on the right track: what changed between when it
worked and when it quit working? This should be a clue. Also, before
pinging it from another host, make sure that ifconfig returns good info
for eth0 and that it can ping itself at eth0's TCP/IP address--if either
of these fail then you already know it's not talking.

One standard trouble-shooting technique for PCI devices is to swap the
cards into different slots.

HTH, Paul