fujitsu-laptop: fingers off backlight if video.ko is serving this functionality

Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/misc/fujitsu-laptop.c

@@ -990,16 +990,16 @@ static int __init fujitsu_init(void)
 
 	/* Register backlight stuff */
 
-	fujitsu->bl_device =
-	    backlight_device_register("fujitsu-laptop", NULL, NULL,
-				      &fujitsubl_ops);
-	if (IS_ERR(fujitsu->bl_device))
-		return PTR_ERR(fujitsu->bl_device);
-
-	max_brightness = fujitsu->max_brightness;
-
-	fujitsu->bl_device->props.max_brightness = max_brightness - 1;
-	fujitsu->bl_device->props.brightness = fujitsu->brightness_level;
+	if (!acpi_video_backlight_support()) {
+		fujitsu->bl_device =
+			backlight_device_register("fujitsu-laptop", NULL, NULL,
+						  &fujitsubl_ops);
+		if (IS_ERR(fujitsu->bl_device))
+			return PTR_ERR(fujitsu->bl_device);
+		max_brightness = fujitsu->max_brightness;
+		fujitsu->bl_device->props.max_brightness = max_brightness - 1;
+		fujitsu->bl_device->props.brightness = fujitsu->brightness_level;
+	}
 
 	ret = platform_driver_register(&fujitsupf_driver);
 	if (ret)
@@ -1035,7 +1035,8 @@ fail_hotkey:
 
 fail_backlight:
 
-	backlight_device_unregister(fujitsu->bl_device);
+	if (fujitsu->bl_device)
+		backlight_device_unregister(fujitsu->bl_device);
 
 fail_platform_device2:
 
@@ -1062,7 +1063,8 @@ static void __exit fujitsu_cleanup(void)
 			   &fujitsupf_attribute_group);
 	platform_device_unregister(fujitsu->pf_device);
 	platform_driver_unregister(&fujitsupf_driver);
-	backlight_device_unregister(fujitsu->bl_device);
+	if (fujitsu->bl_device)
+		backlight_device_unregister(fujitsu->bl_device);
 
 	acpi_bus_unregister_driver(&acpi_fujitsu_driver);