1 files changed, 22 insertions, 7 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index fd48b201eb5..6a0a82f0508 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);