NAME

       acpi_video — ACPI Video Extensions driver

SYNOPSIS

       device acpi_video

DESCRIPTION

       This  driver  uses  the ACPI Video Extensions to control display switching and backlight brightness.  The
       availability  of  the  sysctl(8)  variables  depends  on  the  functions  offered  by  the  host's   ACPI
       implementation.

SYSCTL VARIABLES

       The following sysctls are currently implemented, where ⟨device⟩ is crt, lcd, or tv:

       hw.acpi.video.⟨device⟩.active
               Current state of the output device.

       hw.acpi.video.⟨device⟩.levels
               List of supported brightness levels.

       hw.acpi.video.⟨device⟩.brightness
               Current brightness level of the device.

       hw.acpi.video.⟨device⟩.fullpower
               Preset brightness level to be used in full power mode.

       hw.acpi.video.⟨device⟩.economy
               Preset brightness level to be used in economy mode.

       Defaults for these variables can be set in sysctl.conf(5), which is parsed at boot-time.

SEE ALSO

       acpi(4), loader.conf(5), sysctl.conf(5), sysctl(8)

HISTORY

       The acpi_video driver first appeared in FreeBSD 5.3.

AUTHORS

       The  acpi_video  driver  was  written by Taku YAMAMOTO <taku@cent.saitama-u.ac.jp>.  This manual page was
       written by Mark Santcroos <marks@ripe.net>.

BUGS

       Some systems only perform output switching via SMM even though they export  the  proper  information  via
       ACPI.   On  such  systems,  the  proper hotkeys or OEM driver (for example, acpi_toshiba(4)) must be used
       instead.

Debian                                          November 8, 2004                                   ACPI_VIDEO(4)