Re: [PATCH 0/7][RESEND] acpi, pci: hostbridge hotplug support

[Yinghai Lu <yinghai@kernel.org>]

On Thu, Aug 30, 2012 at 10:42 PM, Bjorn Helgaas <bhelgaas@google.com> wrote:
>
> That's true.  I think we should blindly probe for devices only when
> (1) the system does not have ACPI or (2) the DMI BIOS date is older
> than some date, e.g., 1 Jan 2013.  For new systems with ACPI, we
> should only look at the host bridges described in ACPI.

if those buses do not get scanned, then it should be enough.

how about just removing pcibios_last_bus probing code?

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 937bcec..3f3c460 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -616,16 +616,6 @@ static void __init __pci_mmcfg_init(int early)
        if (list_empty(&pci_mmcfg_list))
                return;

-       if (pcibios_last_bus < 0) {
-               const struct pci_mmcfg_region *cfg;
-
-               list_for_each_entry(cfg, &pci_mmcfg_list, list) {
-                       if (cfg->segment)
-                               break;
-                       pcibios_last_bus = cfg->end_bus;
-               }
-       }
-
        if (pci_mmcfg_arch_init())
                pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
        else {


also Nehalem *EX* and Westmere *EX* does not support EDAC.

so if the user with Nehalem/Westmere Desktop version, want to use to
EDAC, they could just append
pci=last_bus=255 to get those buses scanned.

Yinghai