1 files changed, 22 insertions, 7 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index fd48b201eb53..6a0a82f0508b 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -374,8 +374,11 @@ struct pci_bus * __devinit pci_add_new_bus(struct pci_bus *parent, struct pci_de
         struct pci_bus *child;
 
         child = pci_alloc_child_bus(parent, dev, busnr);
-        if (child)
+        if (child) {
+                spin_lock(&pci_bus_lock);
                 list_add_tail(&child->node, &parent->children);
+                spin_unlock(&pci_bus_lock);
+        }
         return child;
 }
 
@@ -411,7 +414,7 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max
 {
         struct pci_bus *child;
         int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS);
-        u32 buses;
+        u32 buses, i;
         u16 bctl;
 
         pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);
@@ -447,7 +450,7 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max
                         return max;
                 }
 
-                child = pci_alloc_child_bus(bus, dev, busnr);
+                child = pci_add_new_bus(bus, dev, busnr);
                 if (!child)
                         return max;
                 child->primary = buses & 0xFF;
@@ -470,7 +473,11 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max
                 /* Clear errors */
                 pci_write_config_word(dev, PCI_STATUS, 0xffff);
 
-                child = pci_alloc_child_bus(bus, dev, ++max);
+                /* Prevent assigning a bus number that already exists.
+                 * This can happen when a bridge is hot-plugged */
+                if (pci_find_bus(pci_domain_nr(bus), max+1))
+                        return max;
+                child = pci_add_new_bus(bus, dev, ++max);
                 buses = (buses & 0xff000000)
                       | ((unsigned int)(child->primary)     <<  0)
                       | ((unsigned int)(child->secondary)   <<  8)
@@ -501,7 +508,11 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max
                          * as cards with a PCI-to-PCI bridge can be
                          * inserted later.
                          */
-                        max += CARDBUS_RESERVE_BUSNR;
+                        for (i=0; i<CARDBUS_RESERVE_BUSNR; i++)
+                                if (pci_find_bus(pci_domain_nr(bus),
+                                                        max+i+1))
+                                        break;
+                        max += i;
                 }
                 /*
                  * Set the subordinate bus number to its real value.
@@ -757,7 +768,9 @@ pci_scan_single_device(struct pci_bus *bus, int devfn)
          * and the bus list for fixup functions, etc.
          */
         INIT_LIST_HEAD(&dev->global_list);
+        spin_lock(&pci_bus_lock);
         list_add_tail(&dev->bus_list, &bus->devices);
+        spin_unlock(&pci_bus_lock);
 
         return dev;
 }
@@ -878,7 +891,9 @@ struct pci_bus * __devinit pci_scan_bus_parented(struct device *parent, int bus,
                 pr_debug("PCI: Bus %04x:%02x already known\n", pci_domain_nr(b), bus);
                 goto err_out;
         }
+        spin_lock(&pci_bus_lock);
         list_add_tail(&b->node, &pci_root_buses);
+        spin_unlock(&pci_bus_lock);
 
         memset(dev, 0, sizeof(*dev));
         dev->parent = parent;
@@ -911,8 +926,6 @@ struct pci_bus * __devinit pci_scan_bus_parented(struct device *parent, int bus,
 
         b->subordinate = pci_scan_child_bus(b);
 
-        pci_bus_add_devices(b);
-
         return b;
 
 sys_create_link_err:
@@ -922,7 +935,9 @@ class_dev_create_file_err:
 class_dev_reg_err:
         device_unregister(dev);
 dev_reg_err:
+        spin_lock(&pci_bus_lock);
         list_del(&b->node);
+        spin_unlock(&pci_bus_lock);
 err_out:
         kfree(dev);
         kfree(b);