swizzling pci irqs

Kumar Gala galak at kernel.crashing.org
Fri Mar 24 04:15:32 EST 2006

On Mar 23, 2006, at 10:40 AM, David Updegraff wrote:

> Kumar Gala wrote:
>> On Mar 22, 2006, at 2:59 PM, David Updegraff wrote:
>>> Hi.
>>> If there were a noswizzle option to the kernel command line that
>>> resulted in pci scan simply trusting that the bootrom/u-boot had
>>> already
>>> correctly assigned the PCI irqs....  every tom,dick,harry, and
>>> yours-truly wouldn't have to make a new platform to define the
>>> swizzle-o-the-day.  Or have I already missed this argument?
>> Sure, I do this now.  Just don't build pci_auto into your pci support
>> and don't explicitly rescan in your pci setup.  The 83xx pci code
>> under arch/powerpc should effective do this.
>> - kumar
> Hmm; I must be missing something...  cuz to me it looks like pci_32.c
> will allways call pcibios_init, which will will scan the bus, which  
> will
> swizzle irqs if the platform has non-null swizzle and map_irq function
> pointers defined..  Perhaps a setting I've missed somewhere re.
> 'pci_auto', which I thought was a 'ppc' thing, not a 'powerpc'  
> thing..??

Ahh, why do you have swizzle and map_irq functions?  I guess I forgot  
that part.  In my setup I have u-boot do all IRQ assignment (via PCI  
IRQ line register) as well as all BAR config.  I just leave swizzle  
and map_irq null.

- kumar

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