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irq conflict on ze4500 in linux

manish jain_1
Occasional Visitor

irq conflict on ze4500 in linux


I recently bought a HP pavallion ze4500 notebook
and tried installing redhat 9 on it.
I was successfully able to install it.
However, APM and wireless pcmcia card have
some problem which might have to do with BIOS on this notebook.

In the booting process, apm gives a message that BIOS not found. Does it mean that bios on ze4500 does not support APM ? A direct consequence of is that cpu fan is always running in linux, whereas it does shut off in windows.

Seconldy, when I try to load driver for wireless card it gives IRQ conflict with the
ethernet card already present in the system.
How can I resolve this conflict ?

Dave Falloon
Trusted Contributor

Re: irq conflict on ze4500 in linux

Ok for the power management problem. Make sure your BIOS supports the kernel power management you are using, there are two currently, apm and ACPI, the latter is slowly replacing the apm as the standard. Your manual should be able to tell you if you use acpi or apm. If the purchase was recent, then my money is on ACPI.

As far as the IRQ conflict, you may have to patch your kernel to fix this. I ran a search on google but didn't turn up much. Can you post the exact error message you are getting?

I hope that helps,


Clothes make the man, Naked people have little to no effect on society
Bruce Copeland
Trusted Contributor

Re: irq conflict on ze4500 in linux

All the ze4000/ze5000 models use ACPI instead of APM. You can find more information about ACPI and instructions for building an ACPI enabled kernel on my ze4100 web site:

If your ze4500 has an athlon processor, it is likely that the fan WILL run continually, although the fan speed should decrease significantly once you start using an ACPI enabled kernel. Also check to see if there is a bios upgrade for your model on the HP site. Some of the recent ze4000/ze5000 bios upgrades have included some changes in fan/cpu performance.


manish jain_1
Occasional Visitor

Re: irq conflict on ze4500 in linux

Hello Dave,

Regarding IRQ conflict.
I do the following which generates the

insmod pcmcia_core
insmod yenta_socket

Second module gives following messages :
PCI: Found IRQ 11 for device 00:0a:0
IRQ routing conflict for 00:0a:0, have irq 5, want irq 11
Yenta IRQ list 0c98, PCI irq5

Next when I try to load the wireless card driver module, insmod gives me an error saying possible IRQ conflict.

Is there a way to set the interrupt
back to 11 from linux ?
Dave Falloon
Trusted Contributor

Re: irq conflict on ze4500 in linux

So, the built in network controller is on IRQ 11 and your Cardbus controller wants to be on IRQ 11, is that correct?

One quick command to tell you is:

cat /proc/pci

And look for two devices with the same IRQ number.

I don't know of any way to change IRQ's on the fly in linux, I remember having to patch a couple of sony vaio laptops in order to get the USB controller to accept the correct IRQ because of a bug in the firmware. Here is a link to the site with information regarding that fix, perhaps you could rewrite the patch to force your conflicting device to use a different IRQ?

You would have to be pretty comfortable with kernel hacking and minor coding if you wanted to do these changes, I'm afraid. Read through the patch, see what you think. I have yet to come across an online howto for installing linux on your particular laptop version, the closest I have seen was the one posted by Bruce so you are most likely breaking new ground by installing linux on this machine. It may end up that these laptops have the same kind of firmware bug that the vaio's have and a patch will end up being released. Check HP's site for any firmware upgrades.

Take a look at these ideas, but unless you are comfortable with the changes I would wait until someone else has tried to make things work before I started hacking with the kernel. Unless this is a work machine and you are covered by a warrenty/policy that allows you to experiment in order to make it work, in a case such as that I would definately try the pci-irq.c patch.

Clothes make the man, Naked people have little to no effect on society