ACPI / video: add description for brightness_switch_enabled

Add description for video module's parameter brightness_switch_enabled
into kernel-parameters.txt.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 2fe6e767b3d6..7f64e0f0258a 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3229,6 +3229,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
         video=          [FB] Frame buffer configuration
                         See Documentation/fb/modedb.txt.
 
+        video.brightness_switch_enabled= [0,1]
+                        If set to 1, on receiving an ACPI notify event
+                        generated by hotkey, video driver will adjust brightness
+                        level and then send out the event to user space through
+                        the allocated input device; If set to 0, video driver
+                        will only send out the event without touching backlight
+                        brightness level.
+                        default: 1
+
         virtio_mmio.device=
                         [VMMIO] Memory mapped virtio (platform) device.