Intel graphics card brightness control issue
matthias at petermann-it.de
Wed Sep 4 08:30:54 UTC 2013
Zitat von "Ethan W. House" <ehouse at csh.rit.edu>:
> What could be causing my brightness control to not work on my Intel
> graphics card. The acpi values change but no effect takes place.
> ehouse at derpy ~ $ sudo sysctl hw.acpi.video.lcd0.brightness=50
> hw.acpi.video.lcd0.brightness: 100 -> 50
> ehouse at derpy ~ $ sudo sysctl hw.acpi.video.lcd0.active=1
> hw.acpi.video.lcd0.active: 0 -> 0
> I also have an issue were upon resume by machine reboots. I believe the two
> might be related but I am not sure.
> I found a couple of other email chains with similar issues but most of them
> have been inactive for more then a year.
Which Laptop model do you have? This issue appears a bit familiar to
me - I have the same on my Thinkpad. As a workaround you could try
to change the brightness by direct ACPI calls.
* install sysutils/acpi_call
* kldload acpi_call
* acpi_call -p '\VBRU' (Brightness Up)
* acpi_call -p '\VBRD' (Brightness Down)
It might be that these calls are specific to Thinkpads, not sure if
they work with others. You can try to find out with acpidump.
Matthias Petermann <matthias at petermann-it.de>
Ihr Partner für anspruchsvolle IT-Lösungen
www.petermann-it.de - lösungsorientiert, innovativ und erfolgreich
More information about the freebsd-questions