ACPI: cleanups for hotplug

index 5691f16..10df23d 100644
@@ -58,6 +58,7 @@ struct acpi_os_dpc {
 	acpi_osd_exec_callback function;
 	void *context;
 	struct work_struct work;
+	int wait;
 };
 
 #ifdef CONFIG_ACPI_CUSTOM_DSDT

@@ -702,21 +703,8 @@ static void acpi_os_execute_deferred(struct work_struct *work)
 		return;
 	}
 
-	dpc->function(dpc->context);
-	kfree(dpc);
-
-	return;
-}
-
-static void acpi_os_execute_hp_deferred(struct work_struct *work)
-{
-	struct acpi_os_dpc *dpc = container_of(work, struct acpi_os_dpc, work);
-	if (!dpc) {
-		printk(KERN_ERR PREFIX "Invalid (NULL) context\n");
-		return;
-	}
-
-	acpi_os_wait_events_complete(NULL);
+	if (dpc->wait)
+		acpi_os_wait_events_complete(NULL);
 
 	dpc->function(dpc->context);
 	kfree(dpc);

@@ -745,7 +733,6 @@ static acpi_status __acpi_os_execute(acpi_execute_type type,
 	acpi_status status = AE_OK;
 	struct acpi_os_dpc *dpc;
 	struct workqueue_struct *queue;
-	work_func_t func;
 	int ret;
 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 			  "Scheduling function [%p(%p)] for deferred execution.\n",

@@ -778,8 +765,8 @@ static acpi_status __acpi_os_execute(acpi_execute_type type,
 	 */
 	queue = hp ? kacpi_hotplug_wq :
 		(type == OSL_NOTIFY_HANDLER ? kacpi_notify_wq : kacpid_wq);
-	func = hp ? acpi_os_execute_hp_deferred : acpi_os_execute_deferred;
-	INIT_WORK(&dpc->work, func);
+	dpc->wait = hp ? 1 : 0;
+	INIT_WORK(&dpc->work, acpi_os_execute_deferred);
 	ret = queue_work(queue, &dpc->work);
 
 	if (!ret) {

index 10df23d..fe73e28 100644
@@ -698,18 +698,12 @@ void acpi_os_derive_pci_id(acpi_handle rhandle,	/* upper bound  */
 static void acpi_os_execute_deferred(struct work_struct *work)
 {
 	struct acpi_os_dpc *dpc = container_of(work, struct acpi_os_dpc, work);
-	if (!dpc) {
-		printk(KERN_ERR PREFIX "Invalid (NULL) context\n");
-		return;
-	}
 
 	if (dpc->wait)
 		acpi_os_wait_events_complete(NULL);
 
 	dpc->function(dpc->context);
 	kfree(dpc);
-
-	return;
 }
 
 /*******************************************************************************

@@ -738,9 +732,6 @@ static acpi_status __acpi_os_execute(acpi_execute_type type,
 			  "Scheduling function [%p(%p)] for deferred execution.\n",
 			  function, context));
 
-	if (!function)
-		return AE_BAD_PARAMETER;
-
 	/*
 	 * Allocate/initialize DPC structure.  Note that this memory will be
 	 * freed by the callee.  The kernel handles the work_struct list  in a

index 4a89f08..652d104 100644
@@ -366,7 +366,8 @@ static acpi_status acpi_device_notify_fixed(void *data)
 {
 	struct acpi_device *device = data;
 
-	acpi_device_notify(device->handle, ACPI_FIXED_HARDWARE_EVENT, device);
+	/* Fixed hardware devices have no handles */
+	acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
 	return AE_OK;
 }
 

index 652d104..92b4fe2 100644
@@ -1178,6 +1178,7 @@ acpi_add_single_object(struct acpi_device **child,
 {
 	int result = 0;
 	struct acpi_device *device = NULL;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 
 
 	if (!child)

@@ -1311,9 +1312,15 @@ acpi_add_single_object(struct acpi_device **child,
 	}
 
 end:
-	if (!result)
+	if (!result) {
+		acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+			"Adding %s [%s] parent %s\n", dev_name(&device->dev),
+			 (char *) buffer.pointer,
+			 device->parent ? dev_name(&device->parent->dev) :
+					  "(null)"));
 		*child = device;
-	else {
+	} else {
 		kfree(device->pnp.cid_list);
 		kfree(device);
 	}

index 92b4fe2..091d967 100644
@@ -1537,15 +1537,12 @@ int acpi_bus_trim(struct acpi_device *start, int rmdevice)
 }
 EXPORT_SYMBOL_GPL(acpi_bus_trim);
 
-static int acpi_bus_scan_fixed(struct acpi_device *root)
+static int acpi_bus_scan_fixed(void)
 {
 	int result = 0;
 	struct acpi_device *device = NULL;
 	struct acpi_bus_ops ops;
 
-	if (!root)
-		return -ENODEV;
-
 	memset(&ops, 0, sizeof(ops));
 	ops.acpi_op_add = 1;
 	ops.acpi_op_start = 1;

@@ -1596,7 +1593,7 @@ int __init acpi_scan_init(void)
 	/*
 	 * Enumerate devices in the ACPI namespace.
 	 */
-	result = acpi_bus_scan_fixed(acpi_root);
+	result = acpi_bus_scan_fixed();
 
 	if (!result)
 		result = acpi_bus_scan(acpi_root, &ops);

index 091d967..aade372 100644
@@ -470,12 +470,12 @@ struct bus_type acpi_bus_type = {
 	.uevent		= acpi_device_uevent,
 };
 
-static int acpi_device_register(struct acpi_device *device,
-				 struct acpi_device *parent)
+static int acpi_device_register(struct acpi_device *device)
 {
 	int result;
 	struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
 	int found = 0;
+
 	/*
 	 * Linkage
 	 * -------

@@ -520,7 +520,7 @@ static int acpi_device_register(struct acpi_device *device,
 	mutex_unlock(&acpi_device_lock);
 
 	if (device->parent)
-		device->dev.parent = &parent->dev;
+		device->dev.parent = &device->parent->dev;
 	device->dev.bus = &acpi_bus_type;
 	device->dev.release = &acpi_device_release;
 	result = device_register(&device->dev);

@@ -913,8 +913,7 @@ static int acpi_bus_get_flags(struct acpi_device *device)
 	return 0;
 }
 
-static void acpi_device_get_busid(struct acpi_device *device,
-				  acpi_handle handle, int type)
+static void acpi_device_get_busid(struct acpi_device *device, int type)
 {
 	char bus_id[5] = { '?', 0 };
 	struct acpi_buffer buffer = { sizeof(bus_id), bus_id };

@@ -937,7 +936,7 @@ static void acpi_device_get_busid(struct acpi_device *device,
 		strcpy(device->pnp.bus_id, "SLPF");
 		break;
 	default:
-		acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
+		acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
 		/* Clean up trailing underscores (if any) */
 		for (i = 3; i > 1; i--) {
 			if (bus_id[i] == '_')

@@ -995,9 +994,7 @@ static int acpi_dock_match(struct acpi_device *device)
 	return acpi_get_handle(device->handle, "_DCK", &tmp);
 }
 
-static void acpi_device_set_id(struct acpi_device *device,
-			       struct acpi_device *parent, acpi_handle handle,
-			       int type)
+static void acpi_device_set_id(struct acpi_device *device, int type)
 {
 	struct acpi_device_info *info;
 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

@@ -1009,7 +1006,7 @@ static void acpi_device_set_id(struct acpi_device *device,
 
 	switch (type) {
 	case ACPI_BUS_TYPE_DEVICE:
-		status = acpi_get_object_info(handle, &buffer);
+		status = acpi_get_object_info(device->handle, &buffer);
 		if (ACPI_FAILURE(status)) {
 			printk(KERN_ERR PREFIX "%s: Error reading device info\n", __func__);
 			return;

@@ -1065,7 +1062,8 @@ static void acpi_device_set_id(struct acpi_device *device,
 	 * ----
 	 * Fix for the system root bus device -- the only root-level device.
 	 */
-	if (((acpi_handle)parent == ACPI_ROOT_OBJECT) && (type == ACPI_BUS_TYPE_DEVICE)) {
+	if (((acpi_handle)device->parent == ACPI_ROOT_OBJECT) &&
+	     (type == ACPI_BUS_TYPE_DEVICE)) {
 		hid = ACPI_BUS_HID;
 		strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
 		strcpy(device->pnp.device_class, ACPI_BUS_CLASS);

@@ -1194,8 +1192,7 @@ acpi_add_single_object(struct acpi_device **child,
 	device->parent = parent;
 	device->bus_ops = *ops; /* workround for not call .start */
 
-
-	acpi_device_get_busid(device, handle, type);
+	acpi_device_get_busid(device, type);
 
 	/*
 	 * Flags

@@ -1258,7 +1255,7 @@ acpi_add_single_object(struct acpi_device **child,
 	 * Hardware ID, Unique ID, & Bus Address
 	 * -------------------------------------
 	 */
-	acpi_device_set_id(device, parent, handle, type);
+	acpi_device_set_id(device, type);
 
 	/*
 	 * The ACPI device is attached to acpi handle before getting

@@ -1300,8 +1297,7 @@ acpi_add_single_object(struct acpi_device **child,
 			goto end;
 	}
 
-
-	result = acpi_device_register(device, parent);
+	result = acpi_device_register(device);
 
 	/*
 	 * Bind _ADR-Based Devices when hot add

index aade372..b386589 100644
@@ -1188,6 +1188,7 @@ acpi_add_single_object(struct acpi_device **child,
 		return -ENOMEM;
 	}
 
+	device->device_type = type;
 	device->handle = handle;
 	device->parent = parent;
 	device->bus_ops = *ops; /* workround for not call .start */

index 79a6c5e..b145270 100644
@@ -266,7 +266,8 @@ struct acpi_device_wakeup {
 /* Device */
 
 struct acpi_device {
-	acpi_handle handle;
+	int device_type;
+	acpi_handle handle;		/* no handle for fixed hardware */
 	struct acpi_device *parent;
 	struct list_head children;
 	struct list_head node;

index b386589..f563360 100644
@@ -374,15 +374,13 @@ static acpi_status acpi_device_notify_fixed(void *data)
 static int acpi_device_install_notify_handler(struct acpi_device *device)
 {
 	acpi_status status;
-	char *hid;
 
-	hid = acpi_device_hid(device);
-	if (!strcmp(hid, ACPI_BUTTON_HID_POWERF))
+	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
 		status =
 		    acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
 						     acpi_device_notify_fixed,
 						     device);
-	else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEPF))
+	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
 		status =
 		    acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
 						     acpi_device_notify_fixed,

@@ -400,10 +398,10 @@ static int acpi_device_install_notify_handler(struct acpi_device *device)
 
 static void acpi_device_remove_notify_handler(struct acpi_device *device)
 {
-	if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_POWERF))
+	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
 		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
 						acpi_device_notify_fixed);
-	else if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_SLEEPF))
+	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
 		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
 						acpi_device_notify_fixed);
 	else

index f563360..4772b43 100644
@@ -1119,29 +1119,27 @@ static void acpi_device_set_id(struct acpi_device *device, int type)
 	kfree(buffer.pointer);
 }
 
-static int acpi_device_set_context(struct acpi_device *device, int type)
+static int acpi_device_set_context(struct acpi_device *device)
 {
-	acpi_status status = AE_OK;
-	int result = 0;
+	acpi_status status;
+
 	/*
 	 * Context
 	 * -------
 	 * Attach this 'struct acpi_device' to the ACPI object.  This makes
-	 * resolutions from handle->device very efficient.  Note that we need
-	 * to be careful with fixed-feature devices as they all attach to the
-	 * root object.
+	 * resolutions from handle->device very efficient.  Fixed hardware
+	 * devices have no handles, so we skip them.
 	 */
-	if (type != ACPI_BUS_TYPE_POWER_BUTTON &&
-	    type != ACPI_BUS_TYPE_SLEEP_BUTTON) {
-		status = acpi_attach_data(device->handle,
-					  acpi_bus_data_handler, device);
+	if (!device->handle)
+		return 0;
 
-		if (ACPI_FAILURE(status)) {
-			printk(KERN_ERR PREFIX "Error attaching device data\n");
-			result = -ENODEV;
-		}
-	}
-	return result;
+	status = acpi_attach_data(device->handle,
+				  acpi_bus_data_handler, device);
+	if (ACPI_SUCCESS(status))
+		return 0;
+
+	printk(KERN_ERR PREFIX "Error attaching device data\n");
+	return -ENODEV;
 }
 
 static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)

@@ -1262,7 +1260,7 @@ acpi_add_single_object(struct acpi_device **child,
 	 * the corresponding ACPI device by the acpi handle in the course
 	 * of getting the power/wakeup/performance flags.
 	 */
-	result = acpi_device_set_context(device, type);
+	result = acpi_device_set_context(device);
 	if (result)
 		goto end;
 

index 4772b43..7623a80 100644
@@ -911,7 +911,7 @@ static int acpi_bus_get_flags(struct acpi_device *device)
 	return 0;
 }
 
-static void acpi_device_get_busid(struct acpi_device *device, int type)
+static void acpi_device_get_busid(struct acpi_device *device)
 {
 	char bus_id[5] = { '?', 0 };
 	struct acpi_buffer buffer = { sizeof(bus_id), bus_id };

@@ -923,7 +923,7 @@ static void acpi_device_get_busid(struct acpi_device *device, int type)
 	 * The device's Bus ID is simply the object name.
 	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
 	 */
-	switch (type) {
+	switch (device->device_type) {
 	case ACPI_BUS_TYPE_SYSTEM:
 		strcpy(device->pnp.bus_id, "ACPI");
 		break;

@@ -992,7 +992,7 @@ static int acpi_dock_match(struct acpi_device *device)
 	return acpi_get_handle(device->handle, "_DCK", &tmp);
 }
 
-static void acpi_device_set_id(struct acpi_device *device, int type)
+static void acpi_device_set_id(struct acpi_device *device)
 {
 	struct acpi_device_info *info;
 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

@@ -1002,7 +1002,7 @@ static void acpi_device_set_id(struct acpi_device *device, int type)
 	const char *cid_add = NULL;
 	acpi_status status;
 
-	switch (type) {
+	switch (device->device_type) {
 	case ACPI_BUS_TYPE_DEVICE:
 		status = acpi_get_object_info(device->handle, &buffer);
 		if (ACPI_FAILURE(status)) {

@@ -1061,7 +1061,7 @@ static void acpi_device_set_id(struct acpi_device *device, int type)
 	 * Fix for the system root bus device -- the only root-level device.
 	 */
 	if (((acpi_handle)device->parent == ACPI_ROOT_OBJECT) &&
-	     (type == ACPI_BUS_TYPE_DEVICE)) {
+	     (device->device_type == ACPI_BUS_TYPE_DEVICE)) {
 		hid = ACPI_BUS_HID;
 		strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
 		strcpy(device->pnp.device_class, ACPI_BUS_CLASS);

@@ -1189,7 +1189,7 @@ acpi_add_single_object(struct acpi_device **child,
 	device->parent = parent;
 	device->bus_ops = *ops; /* workround for not call .start */
 
-	acpi_device_get_busid(device, type);
+	acpi_device_get_busid(device);
 
 	/*
 	 * Flags

@@ -1252,7 +1252,7 @@ acpi_add_single_object(struct acpi_device **child,
 	 * Hardware ID, Unique ID, & Bus Address
 	 * -------------------------------------
 	 */
-	acpi_device_set_id(device, type);
+	acpi_device_set_id(device);
 
 	/*
 	 * The ACPI device is attached to acpi handle before getting

index 7623a80..35ea4c2 100644
@@ -1170,14 +1170,10 @@ acpi_add_single_object(struct acpi_device **child,
 		       struct acpi_device *parent, acpi_handle handle, int type,
 			struct acpi_bus_ops *ops)
 {
-	int result = 0;
-	struct acpi_device *device = NULL;
+	int result;
+	struct acpi_device *device;
 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 
-
-	if (!child)
-		return -EINVAL;
-
 	device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
 	if (!device) {
 		printk(KERN_ERR PREFIX "Memory allocation error\n");

index 35ea4c2..a57a7ae 100644
@@ -658,6 +658,33 @@ EXPORT_SYMBOL(acpi_bus_unregister_driver);
 /* --------------------------------------------------------------------------
                                  Device Enumeration
    -------------------------------------------------------------------------- */
+static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
+{
+	acpi_status status;
+	int ret;
+	struct acpi_device *device;
+
+	/*
+	 * Fixed hardware devices do not appear in the namespace and do not
+	 * have handles, but we fabricate acpi_devices for them, so we have
+	 * to deal with them specially.
+	 */
+	if (handle == NULL)
+		return acpi_root;
+
+	do {
+		status = acpi_get_parent(handle, &handle);
+		if (status == AE_NULL_ENTRY)
+			return NULL;
+		if (ACPI_FAILURE(status))
+			return acpi_root;
+
+		ret = acpi_bus_get_device(handle, &device);
+		if (ret == 0)
+			return device;
+	} while (1);
+}
+
 acpi_status
 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
 {

@@ -1165,10 +1192,9 @@ static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
 	return 0;
 }
 
-static int
-acpi_add_single_object(struct acpi_device **child,
-		       struct acpi_device *parent, acpi_handle handle, int type,
-			struct acpi_bus_ops *ops)
+static int acpi_add_single_object(struct acpi_device **child,
+				  acpi_handle handle, int type,
+				  struct acpi_bus_ops *ops)
 {
 	int result;
 	struct acpi_device *device;

@@ -1182,7 +1208,7 @@ acpi_add_single_object(struct acpi_device **child,
 
 	device->device_type = type;
 	device->handle = handle;
-	device->parent = parent;
+	device->parent = acpi_bus_get_parent(handle);
 	device->bus_ops = *ops; /* workround for not call .start */
 
 	acpi_device_get_busid(device);

@@ -1390,8 +1416,8 @@ static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
 		}
 
 		if (ops->acpi_op_add)
-			status = acpi_add_single_object(&child, parent,
-				chandle, type, ops);
+			status = acpi_add_single_object(&child, chandle, type,
+							ops);
 		else
 			status = acpi_bus_get_device(chandle, &child);
 

@@ -1444,7 +1470,7 @@ acpi_bus_add(struct acpi_device **child,
 	memset(&ops, 0, sizeof(ops));
 	ops.acpi_op_add = 1;
 
-	result = acpi_add_single_object(child, parent, handle, type, &ops);
+	result = acpi_add_single_object(child, handle, type, &ops);
 	if (!result)
 		result = acpi_bus_scan(*child, &ops);
 

@@ -1540,15 +1566,13 @@ static int acpi_bus_scan_fixed(void)
 	 * Enumerate all fixed-feature devices.
 	 */
 	if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
-		result = acpi_add_single_object(&device, acpi_root,
-						NULL,
+		result = acpi_add_single_object(&device, NULL,
 						ACPI_BUS_TYPE_POWER_BUTTON,
 						&ops);
 	}
 
 	if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
-		result = acpi_add_single_object(&device, acpi_root,
-						NULL,
+		result = acpi_add_single_object(&device, NULL,
 						ACPI_BUS_TYPE_SLEEP_BUTTON,
 						&ops);
 	}

@@ -1574,7 +1598,7 @@ int __init acpi_scan_init(void)
 	/*
 	 * Create the root device in the bus's device tree
 	 */
-	result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT,
+	result = acpi_add_single_object(&acpi_root, ACPI_ROOT_OBJECT,
 					ACPI_BUS_TYPE_SYSTEM, &ops);
 	if (result)
 		goto Done;

index a57a7ae..afd10b5 100644
@@ -1343,7 +1343,7 @@ end:
 	return result;
 }
 
-static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
+static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops)
 {
 	acpi_status status = AE_OK;
 	struct acpi_device *parent = NULL;

@@ -1352,13 +1352,16 @@ static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
 	acpi_handle chandle = NULL;
 	acpi_object_type type = 0;
 	u32 level = 1;
+	int ret;
 
-
-	if (!start)
-		return -EINVAL;
-
-	parent = start;
-	phandle = start->handle;
+	/*
+	 * We must have an acpi_device for the starting node already, and
+	 * we scan its children.
+	 */
+	phandle = handle;
+	ret = acpi_bus_get_device(phandle, &parent);
+	if (ret)
+		return ret;
 
 	/*
 	 * Parse through the ACPI namespace, identify all 'devices', and

@@ -1472,7 +1475,7 @@ acpi_bus_add(struct acpi_device **child,
 
 	result = acpi_add_single_object(child, handle, type, &ops);
 	if (!result)
-		result = acpi_bus_scan(*child, &ops);
+		result = acpi_bus_scan((*child)->handle, &ops);
 
 	return result;
 }

@@ -1483,16 +1486,13 @@ int acpi_bus_start(struct acpi_device *device)
 	int result;
 	struct acpi_bus_ops ops;
 
-
-	if (!device)
-		return -EINVAL;
+	memset(&ops, 0, sizeof(ops));
+	ops.acpi_op_start = 1;
 
 	result = acpi_start_single_object(device);
-	if (!result) {
-		memset(&ops, 0, sizeof(ops));
-		ops.acpi_op_start = 1;
-		result = acpi_bus_scan(device, &ops);
-	}
+	if (!result)
+		result = acpi_bus_scan(device->handle, &ops);
+
 	return result;
 }
 EXPORT_SYMBOL(acpi_bus_start);

@@ -1609,7 +1609,7 @@ int __init acpi_scan_init(void)
 	result = acpi_bus_scan_fixed();
 
 	if (!result)
-		result = acpi_bus_scan(acpi_root, &ops);
+		result = acpi_bus_scan(acpi_root->handle, &ops);
 
 	if (result)
 		acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);

index afd10b5..b97b2ad 100644
@@ -1606,10 +1606,10 @@ int __init acpi_scan_init(void)
 	/*
 	 * Enumerate devices in the ACPI namespace.
 	 */
-	result = acpi_bus_scan_fixed();
+	result = acpi_bus_scan(acpi_root->handle, &ops);
 
 	if (!result)
-		result = acpi_bus_scan(acpi_root->handle, &ops);
+		result = acpi_bus_scan_fixed();
 
 	if (result)
 		acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);

index b97b2ad..c0736f6 100644
@@ -950,10 +950,12 @@ static void acpi_device_get_busid(struct acpi_device *device)
 	 * The device's Bus ID is simply the object name.
 	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
 	 */
-	switch (device->device_type) {
-	case ACPI_BUS_TYPE_SYSTEM:
+	if (!device->parent) {
 		strcpy(device->pnp.bus_id, "ACPI");
-		break;
+		return;
+	}
+
+	switch (device->device_type) {
 	case ACPI_BUS_TYPE_POWER_BUTTON:
 		strcpy(device->pnp.bus_id, "PWRF");
 		break;

@@ -1031,6 +1033,11 @@ static void acpi_device_set_id(struct acpi_device *device)
 
 	switch (device->device_type) {
 	case ACPI_BUS_TYPE_DEVICE:
+		if (!device->parent) {
+			hid = ACPI_SYSTEM_HID;
+			break;
+		}
+
 		status = acpi_get_object_info(device->handle, &buffer);
 		if (ACPI_FAILURE(status)) {
 			printk(KERN_ERR PREFIX "%s: Error reading device info\n", __func__);

@@ -1068,9 +1075,6 @@ static void acpi_device_set_id(struct acpi_device *device)
 	case ACPI_BUS_TYPE_PROCESSOR:
 		hid = ACPI_PROCESSOR_OBJECT_HID;
 		break;
-	case ACPI_BUS_TYPE_SYSTEM:
-		hid = ACPI_SYSTEM_HID;
-		break;
 	case ACPI_BUS_TYPE_THERMAL:
 		hid = ACPI_THERMAL_HID;
 		break;

@@ -1599,7 +1603,7 @@ int __init acpi_scan_init(void)
 	 * Create the root device in the bus's device tree
 	 */
 	result = acpi_add_single_object(&acpi_root, ACPI_ROOT_OBJECT,
-					ACPI_BUS_TYPE_SYSTEM, &ops);
+					ACPI_BUS_TYPE_DEVICE, &ops);
 	if (result)
 		goto Done;
 

index b145270..edca7d5 100644
@@ -72,7 +72,6 @@ enum acpi_bus_device_type {
 	ACPI_BUS_TYPE_POWER,
 	ACPI_BUS_TYPE_PROCESSOR,
 	ACPI_BUS_TYPE_THERMAL,
-	ACPI_BUS_TYPE_SYSTEM,
 	ACPI_BUS_TYPE_POWER_BUTTON,
 	ACPI_BUS_TYPE_SLEEP_BUTTON,
 	ACPI_BUS_DEVICE_TYPE_COUNT

index c0736f6..4bbfde6 100644
@@ -1347,123 +1347,92 @@ end:
 	return result;
 }
 
-static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops)
+static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
+				      void *context, void **return_value)
 {
 	acpi_status status = AE_OK;
-	struct acpi_device *parent = NULL;
-	struct acpi_device *child = NULL;
-	acpi_handle phandle = NULL;
-	acpi_handle chandle = NULL;
+	struct acpi_device *device = NULL;
 	acpi_object_type type = 0;
-	u32 level = 1;
-	int ret;
+	struct acpi_bus_ops *ops = context;
 
-	/*
-	 * We must have an acpi_device for the starting node already, and
-	 * we scan its children.
-	 */
-	phandle = handle;
-	ret = acpi_bus_get_device(phandle, &parent);
-	if (ret)
-		return ret;
+	status = acpi_get_type(handle, &type);
+	if (ACPI_FAILURE(status))
+		return AE_OK;
 
 	/*
-	 * Parse through the ACPI namespace, identify all 'devices', and
-	 * create a new 'struct acpi_device' for each.
+	 * We're only interested in objects that we consider 'devices'.
 	 */
-	while ((level > 0) && parent) {
+	switch (type) {
+	case ACPI_TYPE_ANY:		/* for ACPI_ROOT_OBJECT */
+	case ACPI_TYPE_DEVICE:
+		type = ACPI_BUS_TYPE_DEVICE;
+		break;
+	case ACPI_TYPE_PROCESSOR:
+		type = ACPI_BUS_TYPE_PROCESSOR;
+		break;
+	case ACPI_TYPE_THERMAL:
+		type = ACPI_BUS_TYPE_THERMAL;
+		break;
+	case ACPI_TYPE_POWER:
+		type = ACPI_BUS_TYPE_POWER;
+		break;
+	default:
+		return AE_OK;
+	}
 
-		status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
-					      chandle, &chandle);
+	if (ops->acpi_op_add)
+		status = acpi_add_single_object(&device, handle, type, ops);
+	else
+		status = acpi_bus_get_device(handle, &device);
 
-		/*
-		 * If this scope is exhausted then move our way back up.
-		 */
-		if (ACPI_FAILURE(status)) {
-			level--;
-			chandle = phandle;
-			acpi_get_parent(phandle, &phandle);
-			if (parent->parent)
-				parent = parent->parent;
-			continue;
-		}
+	if (ACPI_FAILURE(status))
+		return AE_CTRL_DEPTH;
 
-		status = acpi_get_type(chandle, &type);
+	if (ops->acpi_op_start && !(ops->acpi_op_add)) {
+		status = acpi_start_single_object(device);
 		if (ACPI_FAILURE(status))
-			continue;
-
-		/*
-		 * If this is a scope object then parse it (depth-first).
-		 */
-		if (type == ACPI_TYPE_LOCAL_SCOPE) {
-			level++;
-			phandle = chandle;
-			chandle = NULL;
-			continue;
-		}
+			return AE_CTRL_DEPTH;
+	}
 
-		/*
-		 * We're only interested in objects that we consider 'devices'.
-		 */
-		switch (type) {
-		case ACPI_TYPE_DEVICE:
-			type = ACPI_BUS_TYPE_DEVICE;
-			break;
-		case ACPI_TYPE_PROCESSOR:
-			type = ACPI_BUS_TYPE_PROCESSOR;
-			break;
-		case ACPI_TYPE_THERMAL:
-			type = ACPI_BUS_TYPE_THERMAL;
-			break;
-		case ACPI_TYPE_POWER:
-			type = ACPI_BUS_TYPE_POWER;
-			break;
-		default:
-			continue;
-		}
+	/*
+	 * If the device is present, enabled, and functioning then
+	 * parse its scope (depth-first).  Note that we need to
+	 * represent absent devices to facilitate PnP notifications
+	 * -- but only the subtree head (not all of its children,
+	 * which will be enumerated when the parent is inserted).
+	 *
+	 * TBD: Need notifications and other detection mechanisms
+	 *      in place before we can fully implement this.
+	 *
+	 * When the device is not present but functional, it is also
+	 * necessary to scan the children of this device.
+	 */
+	if (!device->status.present && !device->status.functional)
+		return AE_CTRL_DEPTH;
 
-		if (ops->acpi_op_add)
-			status = acpi_add_single_object(&child, chandle, type,
-							ops);
-		else
-			status = acpi_bus_get_device(chandle, &child);
+	if (!*return_value)
+		*return_value = device;
+	return AE_OK;
+}
 
-		if (ACPI_FAILURE(status))
-			continue;
+static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops,
+			 struct acpi_device **child)
+{
+	acpi_status status;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	void *device = NULL;
 
-		if (ops->acpi_op_start && !(ops->acpi_op_add)) {
-			status = acpi_start_single_object(child);
-			if (ACPI_FAILURE(status))
-				continue;
-		}
+	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+	printk(KERN_INFO PREFIX "Enumerating devices from [%s]\n",
+	       (char *) buffer.pointer);
 
-		/*
-		 * If the device is present, enabled, and functioning then
-		 * parse its scope (depth-first).  Note that we need to
-		 * represent absent devices to facilitate PnP notifications
-		 * -- but only the subtree head (not all of its children,
-		 * which will be enumerated when the parent is inserted).
-		 *
-		 * TBD: Need notifications and other detection mechanisms
-		 *      in place before we can fully implement this.
-		 */
-		 /*
-		 * When the device is not present but functional, it is also
-		 * necessary to scan the children of this device.
-		 */
-		if (child->status.present || (!child->status.present &&
-					child->status.functional)) {
-			status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,
-						      NULL, NULL);
-			if (ACPI_SUCCESS(status)) {
-				level++;
-				phandle = chandle;
-				chandle = NULL;
-				parent = child;
-			}
-		}
-	}
+	status = acpi_bus_check_add(handle, 0, ops, &device);
+	if (ACPI_SUCCESS(status))
+		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
+				    acpi_bus_check_add, ops, &device);
 
+	if (child)
+		*child = device;
 	return 0;
 }
 

@@ -1471,33 +1440,25 @@ int
 acpi_bus_add(struct acpi_device **child,
 	     struct acpi_device *parent, acpi_handle handle, int type)
 {
-	int result;
 	struct acpi_bus_ops ops;
 
 	memset(&ops, 0, sizeof(ops));
 	ops.acpi_op_add = 1;
 
-	result = acpi_add_single_object(child, handle, type, &ops);
-	if (!result)
-		result = acpi_bus_scan((*child)->handle, &ops);
-
-	return result;
+	acpi_bus_scan(handle, &ops, child);
+	return 0;
 }
 EXPORT_SYMBOL(acpi_bus_add);
 
 int acpi_bus_start(struct acpi_device *device)
 {
-	int result;
 	struct acpi_bus_ops ops;
 
 	memset(&ops, 0, sizeof(ops));
 	ops.acpi_op_start = 1;
 
-	result = acpi_start_single_object(device);
-	if (!result)
-		result = acpi_bus_scan(device->handle, &ops);
-
-	return result;
+	acpi_bus_scan(device->handle, &ops, NULL);
+	return 0;
 }
 EXPORT_SYMBOL(acpi_bus_start);
 

@@ -1600,17 +1561,9 @@ int __init acpi_scan_init(void)
 	}
 
 	/*
-	 * Create the root device in the bus's device tree
-	 */
-	result = acpi_add_single_object(&acpi_root, ACPI_ROOT_OBJECT,
-					ACPI_BUS_TYPE_DEVICE, &ops);
-	if (result)
-		goto Done;
-
-	/*
 	 * Enumerate devices in the ACPI namespace.
 	 */
-	result = acpi_bus_scan(acpi_root->handle, &ops);
+	result = acpi_bus_scan(ACPI_ROOT_OBJECT, &ops, &acpi_root);
 
 	if (!result)
 		result = acpi_bus_scan_fixed();

@@ -1618,6 +1571,5 @@ int __init acpi_scan_init(void)
 	if (result)
 		acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
 
-Done:
 	return result;
 }

index 2876fc7..e2e922d 100644
@@ -93,36 +93,33 @@ int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
 
 EXPORT_SYMBOL(acpi_bus_get_device);
 
-int acpi_bus_get_status(struct acpi_device *device)
+acpi_status acpi_bus_get_status_handle(acpi_handle handle,
+				       unsigned long long *sta)
 {
-	acpi_status status = AE_OK;
-	unsigned long long sta = 0;
-
+	acpi_status status;
 
-	if (!device)
-		return -EINVAL;
+	status = acpi_evaluate_integer(handle, "_STA", NULL, sta);
+	if (ACPI_SUCCESS(status))
+		return AE_OK;
 
-	/*
-	 * Evaluate _STA if present.
-	 */
-	if (device->flags.dynamic_status) {
-		status =
-		    acpi_evaluate_integer(device->handle, "_STA", NULL, &sta);
-		if (ACPI_FAILURE(status))
-			return -ENODEV;
-		STRUCT_TO_INT(device->status) = (int)sta;
+	if (status == AE_NOT_FOUND) {
+		*sta = ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
+		       ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
+		return AE_OK;
 	}
+	return status;
+}
 
-	/*
-	 * According to ACPI spec some device can be present and functional
-	 * even if the parent is not present but functional.
-	 * In such conditions the child device should not inherit the status
-	 * from the parent.
-	 */
-	else
-		STRUCT_TO_INT(device->status) =
-		    ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
-		    ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
+int acpi_bus_get_status(struct acpi_device *device)
+{
+	acpi_status status;
+	unsigned long long sta;
+
+	status = acpi_bus_get_status_handle(device->handle, &sta);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	STRUCT_TO_INT(device->status) = (int) sta;
 
 	if (device->status.functional && !device->status.present) {
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "

@@ -134,10 +131,8 @@ int acpi_bus_get_status(struct acpi_device *device)
 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
 			  device->pnp.bus_id,
 			  (u32) STRUCT_TO_INT(device->status)));
-
 	return 0;
 }
-
 EXPORT_SYMBOL(acpi_bus_get_status);
 
 void acpi_bus_private_data_handler(acpi_handle handle,

index edca7d5..26be825 100644
@@ -326,6 +326,8 @@ extern void unregister_acpi_bus_notifier(struct notifier_block *nb);
 
 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device);
 void acpi_bus_data_handler(acpi_handle handle, u32 function, void *context);
+acpi_status acpi_bus_get_status_handle(acpi_handle handle,
+				       unsigned long long *sta);
 int acpi_bus_get_status(struct acpi_device *device);
 int acpi_bus_get_power(acpi_handle handle, int *state);
 int acpi_bus_set_power(acpi_handle handle, int state);

index 4bbfde6..c078390 100644
@@ -1198,6 +1198,7 @@ static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
 
 static int acpi_add_single_object(struct acpi_device **child,
 				  acpi_handle handle, int type,
+				  unsigned long long sta,
 				  struct acpi_bus_ops *ops)
 {
 	int result;

@@ -1214,61 +1215,21 @@ static int acpi_add_single_object(struct acpi_device **child,
 	device->handle = handle;
 	device->parent = acpi_bus_get_parent(handle);
 	device->bus_ops = *ops; /* workround for not call .start */
+	STRUCT_TO_INT(device->status) = sta;
 
 	acpi_device_get_busid(device);
 
 	/*
 	 * Flags
 	 * -----
-	 * Get prior to calling acpi_bus_get_status() so we know whether
-	 * or not _STA is present.  Note that we only look for object
-	 * handles -- cannot evaluate objects until we know the device is
-	 * present and properly initialized.
+	 * Note that we only look for object handles -- cannot evaluate objects
+	 * until we know the device is present and properly initialized.
 	 */
 	result = acpi_bus_get_flags(device);
 	if (result)
 		goto end;
 
 	/*
-	 * Status
-	 * ------
-	 * See if the device is present.  We always assume that non-Device
-	 * and non-Processor objects (e.g. thermal zones, power resources,
-	 * etc.) are present, functioning, etc. (at least when parent object
-	 * is present).  Note that _STA has a different meaning for some
-	 * objects (e.g. power resources) so we need to be careful how we use
-	 * it.
-	 */
-	switch (type) {
-	case ACPI_BUS_TYPE_PROCESSOR:
-	case ACPI_BUS_TYPE_DEVICE:
-		result = acpi_bus_get_status(device);
-		if (ACPI_FAILURE(result)) {
-			result = -ENODEV;
-			goto end;
-		}
-		/*
-		 * When the device is neither present nor functional, the
-		 * device should not be added to Linux ACPI device tree.
-		 * When the status of the device is not present but functinal,
-		 * it should be added to Linux ACPI tree. For example : bay
-		 * device , dock device.
-		 * In such conditions it is unncessary to check whether it is
-		 * bay device or dock device.
-		 */
-		if (!device->status.present && !device->status.functional) {
-			result = -ENODEV;
-			goto end;
-		}
-		break;
-	default:
-		STRUCT_TO_INT(device->status) =
-		    ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
-		    ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
-		break;
-	}
-
-	/*
 	 * Initialize Device
 	 * -----------------
 	 * TBD: Synch with Core's enumeration/initialization process.

@@ -1347,41 +1308,69 @@ end:
 	return result;
 }
 
-static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
-				      void *context, void **return_value)
+#define ACPI_STA_DEFAULT (ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED | \
+			  ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING)
+
+static int acpi_bus_type_and_status(acpi_handle handle, int *type,
+				    unsigned long long *sta)
 {
-	acpi_status status = AE_OK;
-	struct acpi_device *device = NULL;
-	acpi_object_type type = 0;
-	struct acpi_bus_ops *ops = context;
+	acpi_status status;
+	acpi_object_type acpi_type;
 
-	status = acpi_get_type(handle, &type);
+	status = acpi_get_type(handle, &acpi_type);
 	if (ACPI_FAILURE(status))
-		return AE_OK;
+		return -ENODEV;
 
-	/*
-	 * We're only interested in objects that we consider 'devices'.
-	 */
-	switch (type) {
+	switch (acpi_type) {
 	case ACPI_TYPE_ANY:		/* for ACPI_ROOT_OBJECT */
 	case ACPI_TYPE_DEVICE:
-		type = ACPI_BUS_TYPE_DEVICE;
+		*type = ACPI_BUS_TYPE_DEVICE;
+		status = acpi_bus_get_status_handle(handle, sta);
+		if (ACPI_FAILURE(status))
+			return -ENODEV;
 		break;
 	case ACPI_TYPE_PROCESSOR:
-		type = ACPI_BUS_TYPE_PROCESSOR;
+		*type = ACPI_BUS_TYPE_PROCESSOR;
+		status = acpi_bus_get_status_handle(handle, sta);
+		if (ACPI_FAILURE(status))
+			return -ENODEV;
 		break;
 	case ACPI_TYPE_THERMAL:
-		type = ACPI_BUS_TYPE_THERMAL;
+		*type = ACPI_BUS_TYPE_THERMAL;
+		*sta = ACPI_STA_DEFAULT;
 		break;
 	case ACPI_TYPE_POWER:
-		type = ACPI_BUS_TYPE_POWER;
+		*type = ACPI_BUS_TYPE_POWER;
+		*sta = ACPI_STA_DEFAULT;
 		break;
 	default:
-		return AE_OK;
+		return -ENODEV;
 	}
 
+	return 0;
+}
+
+static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
+				      void *context, void **return_value)
+{
+	struct acpi_bus_ops *ops = context;
+	struct acpi_device *device = NULL;
+	acpi_status status;
+	int type;
+	unsigned long long sta;
+	int result;
+
+	result = acpi_bus_type_and_status(handle, &type, &sta);
+	if (result)
+		return AE_OK;
+
+	if (!(sta & ACPI_STA_DEVICE_PRESENT) &&
+	    !(sta & ACPI_STA_DEVICE_FUNCTIONING))
+		return AE_CTRL_DEPTH;
+
 	if (ops->acpi_op_add)
-		status = acpi_add_single_object(&device, handle, type, ops);
+		status = acpi_add_single_object(&device, handle, type, sta,
+						ops);
 	else
 		status = acpi_bus_get_device(handle, &device);
 

@@ -1394,22 +1383,6 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
 			return AE_CTRL_DEPTH;
 	}
 
-	/*
-	 * If the device is present, enabled, and functioning then
-	 * parse its scope (depth-first).  Note that we need to
-	 * represent absent devices to facilitate PnP notifications
-	 * -- but only the subtree head (not all of its children,
-	 * which will be enumerated when the parent is inserted).
-	 *
-	 * TBD: Need notifications and other detection mechanisms
-	 *      in place before we can fully implement this.
-	 *
-	 * When the device is not present but functional, it is also
-	 * necessary to scan the children of this device.
-	 */
-	if (!device->status.present && !device->status.functional)
-		return AE_CTRL_DEPTH;
-
 	if (!*return_value)
 		*return_value = device;
 	return AE_OK;

@@ -1533,12 +1506,14 @@ static int acpi_bus_scan_fixed(void)
 	if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
 		result = acpi_add_single_object(&device, NULL,
 						ACPI_BUS_TYPE_POWER_BUTTON,
+						ACPI_STA_DEFAULT,
 						&ops);
 	}
 
 	if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
 		result = acpi_add_single_object(&device, NULL,
 						ACPI_BUS_TYPE_SLEEP_BUTTON,
+						ACPI_STA_DEFAULT,
 						&ops);
 	}
 

index c078390..87d3df4 100644
@@ -1354,10 +1354,10 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
 				      void *context, void **return_value)
 {
 	struct acpi_bus_ops *ops = context;
-	struct acpi_device *device = NULL;
-	acpi_status status;
 	int type;
 	unsigned long long sta;
+	struct acpi_device *device;
+	acpi_status status;
 	int result;
 
 	result = acpi_bus_type_and_status(handle, &type, &sta);

@@ -1368,13 +1368,16 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
 	    !(sta & ACPI_STA_DEVICE_FUNCTIONING))
 		return AE_CTRL_DEPTH;
 
-	if (ops->acpi_op_add)
-		status = acpi_add_single_object(&device, handle, type, sta,
-						ops);
-	else
-		status = acpi_bus_get_device(handle, &device);
+	/*
+	 * We may already have an acpi_device from a previous enumeration.  If
+	 * so, we needn't add it again, but we may still have to start it.
+	 */
+	device = NULL;
+	acpi_bus_get_device(handle, &device);
+	if (ops->acpi_op_add && !device)
+		acpi_add_single_object(&device, handle, type, sta, ops);
 
-	if (ACPI_FAILURE(status))
+	if (!device)
 		return AE_CTRL_DEPTH;
 
 	if (ops->acpi_op_start && !(ops->acpi_op_add)) {