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
HISTORY
The acpi_video driver first appeared in
FreeBSD 5.3 and was imported into
DragonFly 2.1.
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.