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.