[Gllug] My eth0's got no interrupt...

[John Winters]

In the words of the old joke:

    My ethernet's got no interrupt
    How does it communicate?
    Terribly!

I've hit an odd problem today with my home server.  I've been aware for
a while that one of the fans was getting noisier and noiser, so today
I shut it down to replace the fan.  I moved the box to my workbench
opened it up, connected everything up (including Ethernet cable) and
powered it up again just to check that I was right about which fan
was on its last elbows.

I was right about the fan, but I then found another thing - the box
wouldn't communicate with the LAN.  I tried a new cable, a new port
on the switch and even changing to a different switch entirely.
Still the same - ifconfig showed that it thought it was transmitting
but the RX packet count stayed stubbornly at zero.

Since this was the on-board ethernet, I fished out a spare ethernet
card, disabled the on-board and shoved that in - same symptoms.  Hotplug
correctly detected the change of card and loaded the right module
but I couldn't receive any packets.  This rang an old bell from the
days of ISA cards and jumpers and things - interrupts.  Checking
/proc/interrupts seemed to indicate that neither card was getting
an interrupt to play with.  The odd thing is that the boot messages
said they were, but /proc/interrupts said they weren't.

Finally I gave the whole machine a body transplant - I moved the HD
into a spare computer and it came up just fine.  A different flavour
of ethernet again (onboard SiS) and it just worked, indicating I
think that the problem is not in the Linux installation.

So - anyone got any idea what could cause this?  The Linux installation
is Sarge running a stock 2.6.8-2-i386 kernel.  The board in the original
PC is a 1.2MHz Mini-ITX with a Nehemiah CPU.

TIA,
John
-- 
Gllug mailing list  -  Gllug at gllug.org.uk
http://lists.gllug.org.uk/mailman/listinfo/gllug