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ACPI_VIDEO(4) FreeBSD Kernel Interfaces Manual ACPI_VIDEO(4)
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.
COMPATIBILITY
In order for acpi_video to attach correctly, acpi_video should be loaded
after any of the DRM kernel modules. This can be achieved by setting the
correct order in rc.conf(5) using the kld_list directive.
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.
FreeBSD 14.0-RELEASE-p6 November 8, 2004 FreeBSD 14.0-RELEASE-p6