Subject: Re: PCI interrupt question

From: Stefan Roese <[email-masked]>
Date: Thu, 3 Dec 2009 08:31:58 +0100

Hi Jeff,

On Thursday 03 December 2009 07:21:56 Jeff Hane wrote:
>  I'm trying to get interrupts working for my PCI device on a 460ex and
> am having problem.  My ISR never triggers.

Which 460EX board is this? Canyonlands or some custom board?
 
> I'm new to PCI(and ppc) and LDD said that I could read the config reg
> INTURRUPT_LINE to get the interrupt assigned to my PCI device.  Well,
> this always reads zero.
> 
> After reading through the code it appears that the interrupt is being
> assigned after reading some information out of the device tree and then
> filling in the irg in the pci_dev structure.

Yes. The device tree has to describe the PCI interrupt layout.
 
> I'm just looking for confirmation that I should be calling request_irq
> with the irq that I found in the pci_dev struct.

Yes.

Canyonlands dts correctly describes the PCI interrupts assignments. If you 
have a custom 460EX board, then you probably have a different interrupt routed 
to the PCI slot. This needs to be described in your device tree file.
 
Cheers,
Stefan