Log message “Disabling IRQ”: what does it mean?

Question

This message appears in my dropdown terminal at seemingly random times when no processes is running in that terminal:

andreas@debianator:~$ 
Message from syslogd@debianator at Feb 24 18:57:58 ...
 kernel:[43089.321139] Disabling IRQ #43

I guess I can disable it from being printed with dmesg -n 1 but what does the message mean?

Solution 1

The message states that the kernel is disabling an interrupt, ie. (usually) ignoring messages from some hardware. This can for example be due to a conflict between two hardware components. You can have more informations about what is using an interrupt with commands like lspci -v or cat /proc/interrupts.

Solution 2

Received a similar message to this a while ago. Discovered it was a hardware issue with how interrupts were passed from the PCI controller to PCI-Express controller (Intel PCI6466 chipset). Check deeper into the logs, look for: irq 43: nobody cared (try booting with the "irqpoll" option)

There are several things that can cause this including incorrect drivers.

Comments

[Bratchley]

Might indicate it's having trouble with some hardware device. Check /var/log/messages (or your distro's equivalent) for a full stack trace and you can check /proc/interrupts to see what that IRQ number is associated with.

[MajorBriggs]

To check deeper into the logs I suppose I should figure out how journalctl works - or is there be a better place to start?

[pacmanwa]

I'm not familiar with how debian does logging. I use RHEL 6 so I typically use "grep -i kernel /var/log/messages | grep -i irq | less"

[Aquarius Power]

it is my "Network controller: Ralink corp. RT2600 802.11 MIMO", it never worked well I dont know why, so I keep and use just a USB WIFI. But I kept that PCI card there. Do you think I should remove that PCI card?

[Uriel]

@AquariusPower If you can not make it work (tweaking its IRQ or avoid conflicts), then better remove it. It will save power and avoid errors. That said I saw this from time to time and never noticed any impact (performance or stability).

[Aquarius Power]

Now I remember, it worked better than USB Wifi to have more stable and lower ping for games, but it was like more than 10years ago if I am not wrong, and that card was installed on an even older PC (that used DDR2 RAM I think). May be I am just deluded by good memories xD, I should just remove that card.

[Aquarius Power]

Today my PC would just not boot, not even open the BIOS setup, would not load the boot loader (grub), but the keyboard was still working (capslock/numlock) on a black screen. I did many things, but only when I removed that old PCI card, it booted again!