compal: fingers off backlight if video.ko is serving this functionality

Signed-off-by: NThomas Renninger <trenn@suse.de>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

drivers/misc/compal-laptop.c

@@ -326,12 +326,14 @@ static int __init compal_init(void)
 
 	/* Register backlight stuff */
 
-	compalbl_device = backlight_device_register("compal-laptop", NULL, NULL,
-						&compalbl_ops);
-	if (IS_ERR(compalbl_device))
-		return PTR_ERR(compalbl_device);
+	if (!acpi_video_backlight_support()) {
+		compalbl_device = backlight_device_register("compal-laptop", NULL, NULL,
+							    &compalbl_ops);
+		if (IS_ERR(compalbl_device))
+			return PTR_ERR(compalbl_device);
 
-	compalbl_device->props.max_brightness = COMPAL_LCD_LEVEL_MAX-1;
+		compalbl_device->props.max_brightness = COMPAL_LCD_LEVEL_MAX-1;
+	}
 
 	ret = platform_driver_register(&compal_driver);
 	if (ret)