Arch Linux

JohnnyRogers

Member

Registered: 2009-10-24

Posts: 32

Screen won't dim w/ Intel KMS [SOLVED]

I have a rather obscure Gateway T-series laptop, with an Intel 965 chip. To get backlight working I had to use acpi_backlight=vendor in Grub, but if KMS is on I can't dim anymore, either with the keys or xbacklight. The keys have no effect, and xbacklight says "No outputs have backlight property".

I haven't noticed any benefits from using KMS, so before now I usually had it off, but it seems that that isn't going to be an option anymore. Am I just SOL now? Anyone dealt with this before?

Last edited by JohnnyRogers (2010-03-14 17:38:00)

measure

Member

Registered: 2009-07-17

Posts: 62

Re: Screen won't dim w/ Intel KMS [SOLVED]

I have a rather obscure Gateway T-series laptop, with an Intel 965 chip. To get backlight working I had to use acpi_backlight=vendor in Grub, but if KMS is on I can't dim anymore, either with the keys or xbacklight. The keys have no effect, and xbacklight says "No outputs have backlight property".

I haven't noticed any benefits from using KMS, so before now I usually had it off, but it seems that that isn't going to be an option anymore. Am I just SOL now? Anyone dealt with this before?

I also have this problem in 2.6.32, but in 2.6.33-RC, this problem seems to be fixed.  Compile it from AUR and see if you get similar results.

Ryan

lustikus

Member

Registered: 2009-11-10

Posts: 262

Re: Screen won't dim w/ Intel KMS [SOLVED]

I also have this problem in 2.6.32, but in 2.6.33-RC, this problem seems to be fixed.  Compile it from AUR and see if you get similar results.

Ryan

thanks for this information, I always wondered why I can't dim with xbacklight on my new laptop where I never had an older kernel than 2.6.32.
I'll wait for the 2.6.33 arch stable though

JohnnyRogers

Member

Registered: 2009-10-24

Posts: 32

Re: Screen won't dim w/ Intel KMS [SOLVED]

I also have this problem in 2.6.32, but in 2.6.33-RC, this problem seems to be fixed.  Compile it from AUR and see if you get similar results.

Ryan

Thanks for the suggestion. I compiled and booted it, but didn't have any luck. I'll continue to futz with it.

JohnnyRogers

Member

Registered: 2009-10-24

Posts: 32

Re: Screen won't dim w/ Intel KMS [SOLVED]

I've found a workaround in this post: http://ubuntuforums.org/showpost.php?p= … ostcount=9 Marking as solved.

Last edited by JohnnyRogers (2010-03-16 10:09:52)

Ultraman

Member

Registered: 2009-12-24

Posts: 242

Re: Screen won't dim w/ Intel KMS [SOLVED]

I've found a workaround, in this post: http://ubuntuforums.org/showpost.php?p= … ostcount=9 Marking as solved.

Might be smart to copy that forumpost here for future reference, in case the link becomes invalid for w/e reason.

Re: No brightness adjustment on samsun n210 (Intel GMA 3150)
Hi,
you can adjust brightness level by sending values directly to device, by setpci:

setpci -s 00:02.0 f4.b=ff

where 00:02.0 is the device address returned by lspci,and ff is a hexadecimal value <0,ff>. I have n210 running Debian, works well

Because it wasn't easy to control brightness this way, I've written a program that adjusts brightness, you can download source from here:
ftp://x.servebeer.com:51300/bright.c
or here:
http://info.wsisiz.edu.pl/~sieluzyc/bright.c

It's a _very simple_ program, but it allows you to increase/decrease brightness by predefinied step, check actual brightness level and set level to a specific value.
It uses the same method that setpci does (write to file in /sys), so plz remember this can be dangerous - use at your own risk.
App does not assign any key shourtcuts, you have to do this manually.

Wcale