[patch 4/4] RFC: PCI: consolidate several pcibios_enable_resources() implementations

[Bjorn Helgaas]

On Monday 18 February 2008 11:31:07 pm Benjamin Herrenschmidt wrote:
> 
> On Mon, 2008-02-18 at 21:39 -0700, Bjorn Helgaas wrote:
> >     powerpc: has a different collision check at (5)
> 
> I've always found the collision check dodgy. I tend to want to keep
> the way powerpc does it here.
> 
> pci_enable_device() should only enable resources that have successfully
> been added to the resource tree (that have passed all the collision
> check etc...). There is a simple & clear indication of that: res->parent
> is non-NULL. I think that is a better check than the test x86 does on
> start and end.
> 
> That is, whatever the arch code decides to use to decide whether
> resources are assigned by firmware or by the first pass assignment code
> or not and collide or not, once that phase is finished (which is the
> case when calling pcibios_enable_device(), having the resource in the
> resource-tree or not is, I believe, the proper way to test whether it's
> a useable resource.

So should x86 adopt that collision check?  I don't hear anything about
actual architecture differences that are behind this implementation
difference.

Bjorn