sony-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>

diff --git a/drivers/misc/sony-laptop.c b/drivers/misc/sony-laptop.c
index 06f07e19dc70748173c373a6dacc07cc25a72935..7bcb81002dcfe32dac89391d975ecc03b5d1a8e9 100644 (file)
--- a/drivers/misc/sony-laptop.c
+++ b/drivers/misc/sony-laptop.c
@@ -1038,7 +1038,11 @@ static int sony_nc_add(struct acpi_device *device)
                goto outinput;
        }
 
-       if (ACPI_SUCCESS(acpi_get_handle(sony_nc_acpi_handle, "GBRT", &handle))) {
+       if (!acpi_video_backlight_support()) {
+               printk(KERN_INFO DRV_PFX "Sony: Brightness ignored, must be "
+                      "controlled by ACPI video driver\n");
+       } else if (ACPI_SUCCESS(acpi_get_handle(sony_nc_acpi_handle, "GBRT",
+                                               &handle))) {
                sony_backlight_device = backlight_device_register("sony", NULL,
                                                                  NULL,
                                                                  &sony_backlight_ops);