{
        struct acpi_video_bus *video = acpi_driver_data(device);
        struct input_dev *input;
-       int keycode;
+       int keycode = 0;
 
        if (!video)
                return;
                break;
 
        default:
-               keycode = KEY_UNKNOWN;
                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                  "Unsupported event [0x%x]\n", event));
                break;
        }
 
        acpi_notifier_call_chain(device, event, 0);
-       input_report_key(input, keycode, 1);
-       input_sync(input);
-       input_report_key(input, keycode, 0);
-       input_sync(input);
+
+       if (keycode) {
+               input_report_key(input, keycode, 1);
+               input_sync(input);
+               input_report_key(input, keycode, 0);
+               input_sync(input);
+       }
 
        return;
 }
        struct acpi_device *device = NULL;
        struct acpi_video_bus *bus;
        struct input_dev *input;
-       int keycode;
+       int keycode = 0;
 
        if (!video_device)
                return;
                keycode = KEY_DISPLAY_OFF;
                break;
        default:
-               keycode = KEY_UNKNOWN;
                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                  "Unsupported event [0x%x]\n", event));
                break;
        }
 
        acpi_notifier_call_chain(device, event, 0);
-       input_report_key(input, keycode, 1);
-       input_sync(input);
-       input_report_key(input, keycode, 0);
-       input_sync(input);
+
+       if (keycode) {
+               input_report_key(input, keycode, 1);
+               input_sync(input);
+               input_report_key(input, keycode, 0);
+               input_sync(input);
+       }
 
        return;
 }
        set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
        set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
        set_bit(KEY_DISPLAY_OFF, input->keybit);
-       set_bit(KEY_UNKNOWN, input->keybit);
 
        error = input_register_device(input);
        if (error)