Pull acpi_bus_register_driver into release branch

Conflicts:

	drivers/acpi/asus_acpi.c
	drivers/acpi/scan.c

drivers/acpi/asus_acpi.c

@@ -1119,6 +1119,8 @@ static int asus_hotk_check(void)
 	return result;
 }
 
+static int asus_hotk_found;
+
 static int asus_hotk_add(struct acpi_device *device)
 {
 	acpi_status status = AE_OK;
@@ -1180,6 +1182,8 @@ static int asus_hotk_add(struct acpi_device *device)
 		}
 	}
 
+	asus_hotk_found = 1;
+
       end:
 	if (result) {
 		kfree(hotk);
@@ -1226,7 +1230,19 @@ static int __init asus_acpi_init(void)
 	asus_proc_dir->owner = THIS_MODULE;
 
 	result = acpi_bus_register_driver(&asus_hotk_driver);
-	if (result < 1) {
+	if (result < 0) {
+		remove_proc_entry(PROC_ASUS, acpi_root_dir);
+		return -ENODEV;
+	}
+
+	/*
+	 * This is a bit of a kludge.  We only want this module loaded
+	 * for ASUS systems, but there's currently no way to probe the
+	 * ACPI namespace for ASUS HIDs.  So we just return failure if
+	 * we didn't find one, which will cause the module to be
+	 * unloaded.
+	 */
+	if (!asus_hotk_found) {
 		acpi_bus_unregister_driver(&asus_hotk_driver);
 		remove_proc_entry(PROC_ASUS, acpi_root_dir);
 		return -ENODEV;

drivers/acpi/scan.c

@@ -142,7 +142,7 @@ static void acpi_device_register(struct acpi_device *device,
 	create_sysfs_device_files(device);
 }
 
-static int acpi_device_unregister(struct acpi_device *device, int type)
+static void acpi_device_unregister(struct acpi_device *device, int type)
 {
 	spin_lock(&acpi_device_lock);
 	if (device->parent) {
@@ -158,7 +158,6 @@ static int acpi_device_unregister(struct acpi_device *device, int type)
 	acpi_detach_data(device->handle, acpi_bus_data_handler);
 	remove_sysfs_device_files(device);
 	kobject_unregister(&device->kobj);
-	return 0;
 }
 
 void acpi_bus_data_handler(acpi_handle handle, u32 function, void *context)
@@ -537,10 +536,9 @@ static int acpi_start_single_object(struct acpi_device *device)
 	return_VALUE(result);
 }
 
-static int acpi_driver_attach(struct acpi_driver *drv)
+static void acpi_driver_attach(struct acpi_driver *drv)
 {
 	struct list_head *node, *next;
-	int count = 0;
 
 	ACPI_FUNCTION_TRACE("acpi_driver_attach");
 
@@ -557,7 +555,6 @@ static int acpi_driver_attach(struct acpi_driver *drv)
 			if (!acpi_bus_driver_init(dev, drv)) {
 				acpi_start_single_object(dev);
 				atomic_inc(&drv->references);
-				count++;
 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 						  "Found driver [%s] for device [%s]\n",
 						  drv->name, dev->pnp.bus_id));
@@ -566,10 +563,9 @@ static int acpi_driver_attach(struct acpi_driver *drv)
 		spin_lock(&acpi_device_lock);
 	}
 	spin_unlock(&acpi_device_lock);
-	return_VALUE(count);
 }
 
-static int acpi_driver_detach(struct acpi_driver *drv)
+static void acpi_driver_detach(struct acpi_driver *drv)
 {
 	struct list_head *node, *next;
 
@@ -591,36 +587,29 @@ static int acpi_driver_detach(struct acpi_driver *drv)
 		}
 	}
 	spin_unlock(&acpi_device_lock);
-	return_VALUE(0);
 }
 
 /**
  * acpi_bus_register_driver - register a driver with the ACPI bus
  * @driver: driver being registered
  *
  * Registers a driver with the ACPI bus.  Searches the namespace for all
- * devices that match the driver's criteria and binds.  Returns the
- * number of devices that were claimed by the driver, or a negative
- * error status for failure.
+ * devices that match the driver's criteria and binds.  Returns zero for
+ * success or a negative error status for failure.
  */
 int acpi_bus_register_driver(struct acpi_driver *driver)
 {
-	int count;
-
 	ACPI_FUNCTION_TRACE("acpi_bus_register_driver");
 
 	if (acpi_disabled)
 		return_VALUE(-ENODEV);
 
-	if (!driver)
-		return_VALUE(-EINVAL);
-
 	spin_lock(&acpi_device_lock);
 	list_add_tail(&driver->node, &acpi_bus_drivers);
 	spin_unlock(&acpi_device_lock);
-	count = acpi_driver_attach(driver);
+	acpi_driver_attach(driver);
 
-	return_VALUE(count);
+	return_VALUE(0);
 }
 
 EXPORT_SYMBOL(acpi_bus_register_driver);
@@ -632,21 +621,16 @@ EXPORT_SYMBOL(acpi_bus_register_driver);
  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
  * devices that match the driver's criteria and unbinds.
  */
-int acpi_bus_unregister_driver(struct acpi_driver *driver)
+void acpi_bus_unregister_driver(struct acpi_driver *driver)
 {
-	ACPI_FUNCTION_TRACE("acpi_bus_unregister_driver");
-
-	if (!driver)
-		return_VALUE(-EINVAL);
-
 	acpi_driver_detach(driver);
 
 	if (!atomic_read(&driver->references)) {
 		spin_lock(&acpi_device_lock);
 		list_del_init(&driver->node);
 		spin_unlock(&acpi_device_lock);
 	}
-	return_VALUE(0);
+	return;
 }
 
 EXPORT_SYMBOL(acpi_bus_unregister_driver);

drivers/char/sonypi.c

@@ -512,7 +512,7 @@ static struct sonypi_device {
 
 #ifdef CONFIG_ACPI
 static struct acpi_device *sonypi_acpi_device;
-static int acpi_enabled;
+static int acpi_driver_registered;
 #endif
 
 static int sonypi_ec_write(u8 addr, u8 value)
@@ -869,7 +869,7 @@ static irqreturn_t sonypi_irq(int irq, void *dev_id, struct pt_regs *regs)
 		sonypi_report_input_event(event);
 
 #ifdef CONFIG_ACPI
-	if (acpi_enabled)
+	if (sonypi_acpi_device)
 		acpi_bus_generate_event(sonypi_acpi_device, 1, event);
 #endif
 
@@ -1551,8 +1551,8 @@ static int __init sonypi_init(void)
 		goto err_free_device;
 
 #ifdef CONFIG_ACPI
-	if (acpi_bus_register_driver(&sonypi_acpi_driver) > 0)
-		acpi_enabled = 1;
+	if (acpi_bus_register_driver(&sonypi_acpi_driver) >= 0)
+		acpi_driver_registered = 1;
 #endif
 
 	return 0;
@@ -1567,7 +1567,7 @@ static int __init sonypi_init(void)
 static void __exit sonypi_exit(void)
 {
 #ifdef CONFIG_ACPI
-	if (acpi_enabled)
+	if (acpi_driver_registered)
 		acpi_bus_unregister_driver(&sonypi_acpi_driver);
 #endif
 	platform_device_unregister(sonypi_platform_device);

include/acpi/acpi_bus.h

@@ -327,7 +327,7 @@ int acpi_bus_set_power(acpi_handle handle, int state);
 int acpi_bus_generate_event(struct acpi_device *device, u8 type, int data);
 int acpi_bus_receive_event(struct acpi_bus_event *event);
 int acpi_bus_register_driver(struct acpi_driver *driver);
-int acpi_bus_unregister_driver(struct acpi_driver *driver);
+void acpi_bus_unregister_driver(struct acpi_driver *driver);
 int acpi_bus_add(struct acpi_device **child, struct acpi_device *parent,
 		 acpi_handle handle, int type);
 int acpi_bus_trim(struct acpi_device *start, int rmdevice);