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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.