Arch Linux

twiistedkaos

Member

Registered: 2006-05-20

Posts: 666

Wth is IRQ

I've noticed at some bootups I see this:

IRQ #21

Although the number varies, sometimes it's different it always fails, it never succeeds. At first I was thinking nothing of it, but I noticed after I actually do bootup my network isn't working. So I type:

/etc/rc.d/network restart

Doesn't work, it freezes when trying to start again. So I try:

/etc/rc.d/network stop
/etc/rc.d/network start

Same thing, but if I restart and don't get a IRQ message the network works fine, it seems when only this IRQ fails I don't have network access, now it doesn't bug me so much just to restart and fix the problem, but I was just wondering what the heck IRQ is, and why it seems to always fail?

profoX

Member

From: Belgium

Registered: 2006-04-13

Posts: 110

Website

Re: Wth is IRQ

I think IRQ has something to do with assigning hardware to addresses.
Do lspci -v and you will see all IRQ's of your pci devices

It could be a problem related to ACPI routing not working correctly.

I'm not sure, but I used to have alot of IRQ#NR disabled on my laptop too. Updating to the -beyond kernel and using custom dsdt tables in the initramfs solved my problem.

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Collecting data is only the first step toward wisdom.
But sharing data is the first step toward community.

Ibex

Member

Registered: 2006-03-02

Posts: 135

Re: Wth is IRQ

An IRQ is an Interrupt Request. This is short-explained a request to hardware to do something.

Without smart tricks, a system has 16 IRQ lines. And thoose IRQ lines sometimes need to be shared. And, sometimes conflicts happens when sharing. Probably the problem will be fixed by moving your network interface card to another PCI slot .

profoX

Member

From: Belgium

Registered: 2006-04-13

Posts: 110

Website

Re: Wth is IRQ

Probably the problem will be fixed by moving your network interface card to another PCI slot .

well, thats something that I couldnt try (laptop)

---

Collecting data is only the first step toward wisdom.
But sharing data is the first step toward community.

twiistedkaos

Member

Registered: 2006-05-20

Posts: 666

Re: Wth is IRQ

An IRQ is an Interrupt Request. This is short-explained a request to hardware to do something.

Without smart tricks, a system has 16 IRQ lines. And thoose IRQ lines sometimes need to be shared. And, sometimes conflicts happens when sharing. Probably the problem will be fixed by moving your network interface card to another PCI slot .

This never happened on any other distro, but alright thanks for the information, I'll try this later

lanrat

Member

From: Poland

Registered: 2003-10-28

Posts: 1,274

Re: Wth is IRQ

You can try to fix it by adding irqpoll option to kernel boot parameters. It worked for me. You need to add it like this to /boot/grub/menu.lst:

title  Arch Linux
root   (hd0,1)
kernel /boot/vmlinuz26 irqpoll root=/dev/sda2 ro
initrd /boot/initrd26.img

IRQ in wikipedia

twiistedkaos

Member

Registered: 2006-05-20

Posts: 666

Re: Wth is IRQ

You can try to fix it by adding irqpoll option to kernel boot parameters. It worked for me. You need to add it like this to /boot/grub/menu.lst:

title  Arch Linux
root   (hd0,1)
kernel /boot/vmlinuz26 irqpoll root=/dev/sda2 ro
initrd /boot/initrd26.img

IRQ in wikipedia

Thanks for the suggestion, I'll try this before switching PCI slots

edit
lanrat, thanks, your suggestion worked