ACPI: fix Supermicro X7DB8+ Boot regression

http://bugzilla.kernel.org/show_bug.cgi?id=7695

Originally we converted bind/unbind to use a new pci bridge driver.
The driver will add/remove _PRT, so we can eventually remove
.bind/.unbind methods.

But we found that some of the _ADR-Based devices don't have _PRT,
i.e. they are not managed by the new ACPI PCI bridge driver.
So that .bind method is not called for some _ADR-Based devices,
which leads to a failure.

Now we make ACPI PCI Root Bridge Driver scan and binds all _ADR-Based devices
once the driver is loaded, in the .add method of ACPI PCI Root Bridge driver.

Extra code path for calling .bind/.unbind when _ADR-Based devices
are hot added/removed is also added.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 9cfc741..2e1a74a 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -151,6 +151,21 @@
 	return AE_OK;
 }
 
+static void acpi_pci_bridge_scan(struct acpi_device *device)
+{
+	int status;
+	struct acpi_device *child = NULL;
+
+	if (device->flags.bus_address)
+		if (device->parent && device->parent->ops.bind) {
+			status = device->parent->ops.bind(device);
+			if (!status) {
+				list_for_each_entry(child, &device->children, node)
+					acpi_pci_bridge_scan(child);
+			}
+		}
+}
+
 static int acpi_pci_root_add(struct acpi_device *device)
 {
 	int result = 0;
@@ -159,6 +174,7 @@
 	acpi_status status = AE_OK;
 	unsigned long value = 0;
 	acpi_handle handle = NULL;
+	struct acpi_device *child;
 
 
 	if (!device)
@@ -175,6 +191,8 @@
 	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 	acpi_driver_data(device) = root;
 
+	device->ops.bind = acpi_pci_bind;
+
 	/* 
 	 * Segment
 	 * -------
@@ -294,6 +312,12 @@
 		result = acpi_pci_irq_add_prt(device->handle, root->id.segment,
 					      root->id.bus);
 
+	/*
+	 * Scan and bind all _ADR-Based Devices
+	 */
+	list_for_each_entry(child, &device->children, node)
+		acpi_pci_bridge_scan(child);
+
       end:
 	if (result) {
 		if (!list_empty(&root->node))