ACPI: video: use .notify method instead of installing handler directly

This patch adds a .notify() method.  The presence of .notify() causes
Linux/ACPI to manage event handlers and notify handlers on our behalf,
so we don't have to install and remove them ourselves.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
CC: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

drivers/acpi/video.c

@@ -79,6 +79,7 @@ module_param(brightness_switch_enabled, bool, 0644);
 static int acpi_video_bus_add(struct acpi_device *device);
 static int acpi_video_bus_remove(struct acpi_device *device, int type);
 static int acpi_video_resume(struct acpi_device *device);
+static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
 
 static const struct acpi_device_id video_device_ids[] = {
 	{ACPI_VIDEO_HID, 0},
@@ -94,6 +95,7 @@ static struct acpi_driver acpi_video_bus = {
 		.add = acpi_video_bus_add,
 		.remove = acpi_video_bus_remove,
 		.resume = acpi_video_resume,
+		.notify = acpi_video_bus_notify,
 		},
 };
 
@@ -1986,17 +1988,15 @@ static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
 	return acpi_video_bus_DOS(video, 0, 1);
 }
 
-static void acpi_video_bus_notify(acpi_handle handle, u32 event, void *data)
+static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
 {
-	struct acpi_video_bus *video = data;
-	struct acpi_device *device = NULL;
+	struct acpi_video_bus *video = acpi_driver_data(device);
 	struct input_dev *input;
 	int keycode;
 
 	if (!video)
 		return;
 
-	device = video->device;
 	input = video->input;
 
 	switch (event) {
@@ -2127,7 +2127,6 @@ static int acpi_video_resume(struct acpi_device *device)
 
 static int acpi_video_bus_add(struct acpi_device *device)
 {
-	acpi_status status;
 	struct acpi_video_bus *video;
 	struct input_dev *input;
 	int error;
@@ -2169,20 +2168,10 @@ static int acpi_video_bus_add(struct acpi_device *device)
 	acpi_video_bus_get_devices(video, device);
 	acpi_video_bus_start_devices(video);
 
-	status = acpi_install_notify_handler(device->handle,
-					     ACPI_DEVICE_NOTIFY,
-					     acpi_video_bus_notify, video);
-	if (ACPI_FAILURE(status)) {
-		printk(KERN_ERR PREFIX
-				  "Error installing notify handler\n");
-		error = -ENODEV;
-		goto err_stop_video;
-	}
-
 	video->input = input = input_allocate_device();
 	if (!input) {
 		error = -ENOMEM;
-		goto err_uninstall_notify;
+		goto err_stop_video;
 	}
 
 	snprintf(video->phys, sizeof(video->phys),
@@ -2218,9 +2207,6 @@ static int acpi_video_bus_add(struct acpi_device *device)
 
  err_free_input_dev:
 	input_free_device(input);
- err_uninstall_notify:
-	acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
-				   acpi_video_bus_notify);
  err_stop_video:
 	acpi_video_bus_stop_devices(video);
 	acpi_video_bus_put_devices(video);
@@ -2235,7 +2221,6 @@ static int acpi_video_bus_add(struct acpi_device *device)
 
 static int acpi_video_bus_remove(struct acpi_device *device, int type)
 {
-	acpi_status status = 0;
 	struct acpi_video_bus *video = NULL;
 
 
@@ -2245,11 +2230,6 @@ static int acpi_video_bus_remove(struct acpi_device *device, int type)
 	video = acpi_driver_data(device);
 
 	acpi_video_bus_stop_devices(video);
-
-	status = acpi_remove_notify_handler(video->device->handle,
-					    ACPI_DEVICE_NOTIFY,
-					    acpi_video_bus_notify);
-
 	acpi_video_bus_put_devices(video);
 	acpi_video_bus_remove_fs(device);