@@ -1979,6 +1979,10 @@ acpi_video_switch_brightness(struct acpi_video_device *device, int event)
unsigned long long level_current, level_next;
int result = -EINVAL;
+ /* no warning message if acpi_backlight=vendor is used */
+ if (!acpi_video_backlight_support())
+ return 0;
+
if (!device->brightness)
goto out;