Re: [PATCH -v2] x86, pci: Handle fallout pci devices with peer rootbus

From: H. Peter Anvin
Date: Mon Jun 14 2010 - 14:40:35 EST


On 06/14/2010 11:34 AM, Bjorn Helgaas wrote:
>
> I made the point there that an HT chain may contain multiple HT/PCI
> host bridges, but you are stuck on the idea that "one HT chain == one
> PCI root bus."
>
> I have not found the "one PCI host bridge per HT chain" requirement
> in the HT spec (if you find it, please point me to it).
>
> If an HT chain may contain multiple HT/PCI host bridges, then it's
> obvious that the HT host bridge registers read by amd_bus.c don't
> contain enough information to correctly assign address space to the
> PCI root buses.
>

A HT-to-PCI bridge appears as a PCI-to-PCI bridge (i.e. a Header Type 1
device), not as a host bridge (a Header Type 0 device).

That is at least the software model as defined.

-hpa
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/