2011/8/24 Bjorn Helgaas <bhelgaas@xxxxxxxxxx>:
> I like this approach a lot. Thanks for working it up. It's a nice
> small change with very little impact to other architectures, and you
> have a nice clear changelog. You might mention something about the
> fact that by default, the bus starts out with all of ioport_resource
> and iomem_resource -- that will mean something to people who know how
> host bridges work.
Thanks! And I'll add this info to the patch description.
> Using pci_bus_add_resource() here *seems* like it should be the right
> thing, but I don't think it will work correctly.
>
> The problem is that struct pci_bus has both a table of resources
> (bus->resource[]) *and* a list (bus->resources).
> pci_bus_add_resource() always puts the new resource on the list, but
> various arch code still references the table directly, e.g., sparc has
> "pbus->resource[0] = &pbm->io_space" in pcibios_fixup_bus().
>
> As written, I think this patch will break sparc because the host
> bridge will end up with both pbm->io_space (in the table) and
> ioport_resource (in the list).
Good catch! I overlooked this point.
> I think something like this would work, though:
>
> if (bus_res)
> list_add_tail(&b->resources, &bus_res->list);
> else {
> b->resource[0] = &ioport_resource;
> b->resource[1] = &iomem_resource;
> }
Yes, it should work.
Thanks again for your time,
Deng-Cheng
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
