Op 23-06-10 17:38, Alex Deucher schreef: > On Wed, Jun 23, 2010 at 11:11 AM, Xavier Bestel <[email protected]> wrote: >> On Wed, 2010-06-23 at 00:41 +0200, Éric Piel wrote: >>> Op 22-06-10 23:56, giovanni_re schreef: >>>> Didn't get an answer on KUbuntu list, so hopefully someone here might >>>> have a suggestion. >>>> >>>> == >>>> I've just installed an Apple Cinema Display (LCD) monitor. This is a 5 >>>> year old monitor. >>>> Using KUbuntu 10.4 >>>> >>>> The apple website indicates this monitor has: >>>> User controls (hardware and software): >>>> Display power, system sleep, system wake, brightness and display tilt >>>> http://support.apple.com/kb/SP79 >>>> http://support.apple.com/kb/SP77 >>>> >>>> Brightness is what I want to turn down. >>>> >>>> Looking in the >>>> KDE System Settings > General > Computer Administration > Display > Size >>>> & orientation > DVI-0 >>>> >>>> there is no adjustment for brightness. >>>> >>>> Anyone know how to decrease brightness on this? >>>> >>>> What sw manages the KDE system settings for Displays? KDE? X? >>>> >>>> Is there a way to turn down the brightness using some X config? >>>> >>>> Is there a GUI for doing X configuration settings? >>> >>> Why do you think you can change the brightness via software? It is very >>> unsual for separate monitors to support this. Isn't there some buttons >>> on the monitor to do that?! >>> >>> Anyway, if you really want to do this by software: >>> * DDC/CI is the key. Try using ddccontrol. But your graphic card must >>> support it, and your monitor too. In practice, it's unlikely to work. >> >> Well, it works quite well on my Dell 24" (radeon driver), even if it has >> front controls. >> I think more monitors support this than you think. The problems are: >> - KMS/Xorg don't support it, so you have to be root for ddccontrol to >> work. > > KMS exposes the ddc i2c buses via sysfs, so you can access them > directly. It would be pretty easy to add some common ddc/ci code to > the drm and then expose whatever controls are found via sysfs and > xrandr as connector attributes similar to the edid. I'd be happy to > help if someone more familiar with ddc/ci wanted to get the ball > rolling. Could be useful. Becareful though, apparently, there was already a DDC driver in the kernel and it was kicked out because everything can be done in userspace: http://www.lm-sensors.org/browser/i2c-tools/trunk/eeprom/ddcmon
By the way, on my i945, I modprobe'd i2c-dev, the 2 i2c's of the graphic card seems being fine in sysfs, but when I run "ddccontrol /dev/i2c-0", it behaves exactly as if the file didn't exist, because apparently it tries to do some weird things with ddcpci :-S Eric _______________________________________________ [email protected]: X.Org support Archives: http://lists.freedesktop.org/archives/xorg Info: http://lists.freedesktop.org/mailman/listinfo/xorg Your subscription address: [email protected]
