[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: Reassigning IRQ

> Hello everyone. I am the newbie who asked for help settup up two ether
> cards for a firewall about a week ago. Thank you for all your help. The
> advice I received helped me identify my problem. But alas, I don't have
> the skill to fix it (sigh).

You will when we're done. :)

> My second card (a 3Com 3c509B ISA card) isn't being initialized. As
> several posters suggested, I believe the problem to be an IRQ conflict.
> The situation:
> - At boot up, I get the message of failure for initialization of the
> second card (eth1).
> - After typing the command "ifconfig eth1 netmask
> up", I get the response "SIOCSIFFLAGS: Resources
> temporarily unavailable".

Normal for an IRQ conflict or an uninitialized card.

> - The dmesg command than shows that the card has been allocated an IRQ
> of 10, which is already taken up by an external SCSI device (as shown by
> "cat /proc/interrupts")

That would be bad. :)

> - Using netcfg, I tried to activate the second card, but I got an
> initialization delayed response.
> - The lsmod 3c509 command gives the status of the 3c509 module as unused.

Again correct if the module insertion was blown.

> As it was so kindly suggested, I disabled the PnP function using the
> Window disks that came with the card. The output said that PnP was
> successfully disabled. The card was still was not assigned a new IRQ
> after start up.

You need to run the 3c5x9cfg util again.  Disabling PnP is the first half
of setting up the card -- the second half is setting the IRQ and I/O port
to something you can live with.  Make sure you print or copy
/proc/interrupts and /proc/ioports so that you know what is taken and what
is free.

> My problem is that I do not know how to manually set the IRQ to another
> number. I tried using the Adapter2 tab in linuxconf, and have added an
> option statement in /etc/conf.modules (options 3c509 irq=5) to no avail.

Altering the IRQ in the driver is intended for the card when it is PnP
mode.  You can tell the driver to look at IRQ 5, but if the card isn't set
to that IRQ...

> I even physcially took out the offending SCSI card, only to have eth0
> reassigned the IRQ of 10.

The card isn't being "assigned" anything here.  Once you disable the PnP,
the card uses the default hard settings of IRQ 10 (and the default I/O
port setting, which I forget).  This harkens back to the black old days of
ISA, where *nothing* in the system was automatically assigned, and you had
to set and keep track of everything you set on each card.  This is why you
will occassionally see even today cards or stickers on the side of very
old machines with this information on them.

> My questions:
> How can I force a different IRQ?

Use the 3c5x9cfg DOS tool located on the second disk of the 3Com driver
disk set.

> How can I initiaze eth1? Will setting a different IRQ allow me to
> initiaze eth1?

You're probably in the same boat with eth1, if it is also a 3c509-type
card.  3c5x9cfg should detect both cards and configure both cards.
Disable PnP on both, and set both to free IRQs and I/O ports.  You
may need to pull the SCSI adapter temporarily while all this going on.

> Is there a way to do so using the Window disks that came with the driver
> (I tried after booting up with a Windows boot disk, but couldn't figure
> out how to set a new IRQ).

Yes.  The 3c5x9cfg program, which you might have used to disable the PnP
on the card.  The interface is text-graphics-based and not that great, but
the options are there.  I can build a walk-through if you need one.  Note
that unless PnP has been disabled, none of the IRQ and I/O port settings
options will be available.

> PS When I restart the network services using /etc/rc.d/init.d/network
> restart command, both eth0 and eth1 are brought up with no problems.

If the modules are inserted, the network interfaces will generally start
-- but not do anything, since the relationship to the hardware isn't
configured right.  Can you do anything on the network with these
interfaces up?


Matt Drew
Executive Officer
Red Hat Consumer Services

[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]