unexpected IRQ trap at vector

Lonni J Friedman netllama at gmail.com
Fri Jul 28 22:28:33 UTC 2006


On 7/27/06, Andy Green <andy at warmcat.com> wrote:
> Lonni J Friedman wrote:
> > I just performed a fresh FC5-x86 installation on a Toshiba Tecra M3
> > notebook.  All was good until I updated to the latest kernel.  Now i'm
> > seeing this error in dmesg about 10 times/second, non-stop:
> > unexpected IRQ trap at vector 12
> >
> > Anyone have any ideas on what is going on here?  I tried booting with
> > both noapic and acpi=off, and neither made any difference.
>
> Basically a device on IRQ 12 is spamming you with interrupts, Linux
> believes that is an "Illegal vector":
>
>          /*
>           * 'what should we do if we get a hw irq event on an illegal
> vector'.
>           * each architecture has to answer this themself.
>           */
>
> For i386 the answer is to print that dmesg message.
>
> What is an "illegal vector"?  I guess one that does not have a driver
> ready to service the interrupts.
>
> Normally hardware devices don't start issuing interrupts until they are
> recognized and asked to do so by a driver.
>
> What does
>
> cat /proc/interrupts
>
> say?  What devices are on your box that you are not using under Linux?
> How about a PS/2-style mouse-like device or somesuch?  Anything in
> /var/log/messages at boot-time about devices not being recognized properly?

Thanks for your reply.  IRQ 12 is owned by:
 12:        115    IO-APIC-edge  i8042

However, the odd thing that I've discovered is that if the onboard
Marvell NIC using the sky2 driver doesn't come up at boot, then all of
these errors are eliminated completely.  sky2 isn't using IRQ12:
169:          0   IO-APIC-level  uhci_hcd:usb4, sky2

So i'm still rather confused on this.


-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
L. Friedman                                    netllama at gmail.com
LlamaLand                       http://netllama.linux-sxs.org




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