1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 47c1071ad84e..54404917be9a 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -55,12 +55,19 @@ pbus_assign_resources_sorted(struct pci_bus *bus)
         list_for_each_entry(dev, &bus->devices, bus_list) {
                 u16 class = dev->class >> 8;
 
-                /* Don't touch classless devices or host bridges or ioapics.  */
+                /* Don't touch classless devices or host bridges. */
                 if (class == PCI_CLASS_NOT_DEFINED ||
-                    class == PCI_CLASS_BRIDGE_HOST ||
-                    class == PCI_CLASS_SYSTEM_PIC)
+                    class == PCI_CLASS_BRIDGE_HOST)
                         continue;
 
+                /* Don't touch ioapics if it has the assigned resources. */
+                if (class == PCI_CLASS_SYSTEM_PIC) {
+                        res = &dev->resource[0];
+                        if (res[0].start || res[1].start || res[2].start ||
+                            res[3].start || res[4].start || res[5].start)
+                                continue;
+                }
+
                 pdev_sort_resources(dev, &head);
         }