diff --git a/drivers/acpi/pci_bind.c b/drivers/acpi/pci_bind.c
index 703d2a3e8012e3a89b30b94b9fbf454248897281..6eb58ef366efeb20f6a3f77ad23e6f1afe9fc152 100644
--- a/drivers/acpi/pci_bind.c
+++ b/drivers/acpi/pci_bind.c
@@ -124,7 +124,7 @@ static int acpi_pci_bind(struct acpi_device *device)
 {
 	acpi_status status;
 	acpi_handle handle;
-	unsigned char bus;
+	struct pci_bus *bus;
 	struct pci_dev *dev;
 
 	dev = acpi_get_pci_dev(device->handle);
@@ -157,11 +157,11 @@ static int acpi_pci_bind(struct acpi_device *device)
 		goto out;
 
 	if (dev->subordinate)
-		bus = dev->subordinate->number;
+		bus = dev->subordinate;
 	else
-		bus = dev->bus->number;
+		bus = dev->bus;
 
-	acpi_pci_irq_add_prt(device->handle, pci_domain_nr(dev->bus), bus);
+	acpi_pci_irq_add_prt(device->handle, bus);
 
 out:
 	pci_dev_put(dev);
diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index 51b9f8280f887cfd6649a39446e7e081d52fe3b6..3ed944cefb364cb3ebfa56084cfa267c6e637a2d 100644
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -182,7 +182,7 @@ static void do_prt_fixups(struct acpi_prt_entry *entry,
 	}
 }
 
-static int acpi_pci_irq_add_entry(acpi_handle handle, int segment, int bus,
+static int acpi_pci_irq_add_entry(acpi_handle handle, struct pci_bus *bus,
 				  struct acpi_pci_routing_table *prt)
 {
 	struct acpi_prt_entry *entry;
@@ -196,8 +196,8 @@ static int acpi_pci_irq_add_entry(acpi_handle handle, int segment, int bus,
 	 * 1=INTA, 2=INTB.  We use the PCI encoding throughout, so convert
 	 * it here.
 	 */
-	entry->id.segment = segment;
-	entry->id.bus = bus;
+	entry->id.segment = pci_domain_nr(bus);
+	entry->id.bus = bus->number;
 	entry->id.device = (prt->address >> 16) & 0xFFFF;
 	entry->pin = prt->pin + 1;
 
@@ -242,7 +242,7 @@ static int acpi_pci_irq_add_entry(acpi_handle handle, int segment, int bus,
 	return 0;
 }
 
-int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
+int acpi_pci_irq_add_prt(acpi_handle handle, struct pci_bus *bus)
 {
 	acpi_status status;
 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
@@ -271,7 +271,7 @@ int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
 
 	entry = buffer.pointer;
 	while (entry && (entry->length > 0)) {
-		acpi_pci_irq_add_entry(handle, segment, bus, entry);
+		acpi_pci_irq_add_entry(handle, bus, entry);
 		entry = (struct acpi_pci_routing_table *)
 		    ((unsigned long)entry + entry->length);
 	}
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index f23fcc5c9674d118aad9e3e8b9ad542f56d28807..f341b0756c9eaec39da29d3a97fff3f7691d9cdd 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -614,8 +614,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 	 */
 	status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
 	if (ACPI_SUCCESS(status))
-		result = acpi_pci_irq_add_prt(device->handle, root->id.segment,
-					      root->id.bus);
+		result = acpi_pci_irq_add_prt(device->handle, root->bus);
 
 	/*
 	 * Scan and bind all _ADR-Based Devices
diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h
index 2740a289483798cb1833e8ce643c73037702c0ca..686a960bde39bd208640cc21a4493f74816bf32e 100644
--- a/include/acpi/acpi_drivers.h
+++ b/include/acpi/acpi_drivers.h
@@ -91,7 +91,7 @@ int acpi_pci_link_free_irq(acpi_handle handle);
 
 /* ACPI PCI Interrupt Routing (pci_irq.c) */
 
-int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus);
+int acpi_pci_irq_add_prt(acpi_handle handle, struct pci_bus *bus);
 void acpi_pci_irq_del_prt(int segment, int bus);
 
 /* ACPI PCI Device Binding (pci_bind.c) */