x86_64: don't need set default res if only have one root bus

if there's only one root bus there's no need to split resources.

This patch fixes the issue described at:

  http://lkml.org/lkml/2008/4/10/304

Reported-and-bisected-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/x86/pci/k8-bus_64.c b/arch/x86/pci/k8-bus_64.c
index 84b2030fc2f0..4e64c58e17a0 100644
--- a/arch/x86/pci/k8-bus_64.c
+++ b/arch/x86/pci/k8-bus_64.c
@@ -69,7 +69,8 @@ void set_pci_bus_resources_arch_default(struct pci_bus *b)
         int j;
         struct pci_root_info *info;
 
-        if (!pci_root_num)
+        /* if only one root bus, don't need to anything */
+        if (pci_root_num < 2)
                 return;
 
         for (i = 0; i < pci_root_num; i++) {