[PATCH 08/18] PCI, powerpc: Register busn_res for root buses

[Bjorn Helgaas]

On Mon, Feb 27, 2012 at 7:09 PM, Yinghai Lu <yinghai at kernel.org> wrote:
> Signed-off-by: Yinghai Lu <yinghai at kernel.org>
> Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> Cc: Paul Mackerras <paulus at samba.org>
> Cc: linuxppc-dev at lists.ozlabs.org
> ---
>  arch/powerpc/kernel/pci-common.c |    7 ++++++-
>  1 files changed, 6 insertions(+), 1 deletions(-)
>
> diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
> index 910b9de..ae5ae5f 100644
> --- a/arch/powerpc/kernel/pci-common.c
> +++ b/arch/powerpc/kernel/pci-common.c
> @@ -1660,6 +1660,8 @@ void __devinit pcibios_scan_phb(struct pci_controller *hose)
>        bus->secondary = hose->first_busno;
>        hose->bus = bus;
>
> +       pci_bus_insert_busn_res(bus, hose->first_busno, hose->last_busno);
> +
>        /* Get probe mode and perform scan */
>        mode = PCI_PROBE_NORMAL;
>        if (node && ppc_md.pci_probe_mode)
> @@ -1670,8 +1672,11 @@ void __devinit pcibios_scan_phb(struct pci_controller *hose)
>                of_scan_bus(node, bus);
>        }
>
> -       if (mode == PCI_PROBE_NORMAL)
> +       if (mode == PCI_PROBE_NORMAL) {
> +               pci_bus_update_busn_res_end(bus, 255);
>                hose->last_busno = bus->subordinate = pci_scan_child_bus(bus);
> +               pci_bus_update_busn_res_end(bus, bus->subordinate);
> +       }

There's a lot of powerpc code that does this:

    bus_range = of_get_property(pcictrl, "bus-range", &len);
    hose->first_busno = bus_range[0];
    hose->last_busno = bus_range[1];

That *looks* like it is discovering the bus number aperture.  Is it?
If it is, why are we using the largest bus number found by
pci_scan_child_bus() rather than "last_busno"?

Bjorn