API to turn off the display

Mark Santcroos marks at ripe.net
Fri Jan 30 01:15:06 PST 2004

On Thu, Jan 29, 2004 at 06:07:27AM +0900, Taku YAMAMOTO wrote:
> I wrote a driver that handles what John told.
> http://access.cent.saitama-u.ac.jp/~taku/freebsd/acpi_vid-20031013.tar.gz
> MD5 (acpi_vid-20031013.tar.gz) = adbfa6931e505544fb784e00c7b974e7
> This driver uses ACPI video extension to control display switching and
> backlight brightness. So working ACPI is a requisition for this driver.
> Whether it does or does not work depends heavily on how well the BIOS written,
> however, I hope it worth trying.

Tried it on my Latitude C640.

acpi_vid0: <ACPI video extension> on acpi0
found CRT monitor(100), detectable by BIOS, head #0
found LCD panel(110), detectable by BIOS, head #0
unknown: not probed (disabled)
unknown: not probed (disabled)
unknown: not probed (disabled)
unknown: not probed (disabled)

Toggling the lcd0.active sysctl to "0", turns the screen off for a
second, but then it turns on again. The sysctl stays as "0" though.
Setting it "from 0 to 0" after that blanks the screen for a second

Effect on console and in X is similar.


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