APIC, x86: How to change the IRQ of one board when BIOS can't ?

APIC, x86: How to change the IRQ of one board when BIOS can't ?

[Serge Noiraud]

Hi,

I get sometimes an APIC error on CPU 1. for IRQ 169, I get 4 modules : 3 USB 
and one Nvidia ( I know, you dislike that). I would like to affect another 
IRQ to the nvidia card to see if the problem is nvidia or not. I don't want 
to modify the others IRQ.
I can't from the BIOS. I red Documentation/i386/IO-APIC.txt but I'm not sure 
it is possible.
What is the best method to do that ? is pirq the solution ? how ?

Re: APIC, x86: How to change the IRQ of one board when BIOS can't ?

[Robert Hancock]

Serge Noiraud wrote:
> Hi,
> 
> I get sometimes an APIC error on CPU 1. for IRQ 169, I get 4 modules : 3 USB 
> and one Nvidia ( I know, you dislike that). I would like to affect another 
> IRQ to the nvidia card to see if the problem is nvidia or not. I don't want 
> to modify the others IRQ.
> I can't from the BIOS. I red Documentation/i386/IO-APIC.txt but I'm not sure 
> it is possible.
> What is the best method to do that ? is pirq the solution ? how ?

If the BIOS can't do it, it may not be possible at all, i.e. the 
interrupt lines may be hard wired that way on the motherboard.

-- 
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/

RE: APIC, x86: How to change the IRQ of one board when BIOS can't ?

[Brown, Len]

>If the BIOS can't do it, it may not be possible at all, i.e. the 
>interrupt lines may be hard wired that way on the motherboard.

Note that physical interrupt wires are associated with physical
slots.  So if the devices in question are pluggable and you
have multiple slots, then moving devices between slots may
give devices different interrupt lines.  (or they can be all
wired together and this will make no difference)

But it is unusual for PCI IRQs to have lots of sharing in IOAPIC mode.
I didn't see the message preceeding this one -- did you post your
/proc/interrupts and output from dmesg -s64000?

thanks,
-Len

Re: APIC, x86: How to change the IRQ of one board when BIOS can't ?

[Zwane Mwaikambo]

On Mon, 5 Dec 2005, Serge Noiraud wrote:

> I get sometimes an APIC error on CPU 1. for IRQ 169, I get 4 modules : 3 USB 
> and one Nvidia ( I know, you dislike that). I would like to affect another 
> IRQ to the nvidia card to see if the problem is nvidia or not. I don't want 
> to modify the others IRQ.
> I can't from the BIOS. I red Documentation/i386/IO-APIC.txt but I'm not sure 
> it is possible.
> What is the best method to do that ? is pirq the solution ? how ?

This most likely has nothing to do with the interrupt routing, do the APIC  
errors occur when you boot with 'noapic'? Also what are the two numbers 
after the APIC error?