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>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 2fe6e767b3d6013f3d1023c2e518b0466fa27e2f..7f64e0f0258ae013bccc5766128420d7efaf12a4 100644 (file)
--- 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.