Pull 5571 into release branch

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index f051b15..d10668f 100644 (file)
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -812,7 +812,7 @@ acpi_video_device_write_brightness(struct file *file,
 
        ACPI_FUNCTION_TRACE("acpi_video_device_write_brightness");
 
-       if (!dev || count + 1 > sizeof str)
+       if (!dev || !dev->brightness || count + 1 > sizeof str)
                return_VALUE(-EINVAL);
 
        if (copy_from_user(str, buffer, count))