Ubuntu
linux-source-2.6.22 package

  1. Bug #173652
  2. Comment #120

Comment 120 for bug 173652

Revision history for this message
Sean Coleman (sean-coleman) wrote : Re: Unable to adjust screen brightness on recent Sony Vaio notebooks, Intel GMA adapter

I have a fairly recent model: Sony VGN-NR498E, Intel X3100.

With a fresh install of 8.10, the function keys cause the backlight OSD to move up and down properly, however there is no adjustment to the backlight.

If I use the command "xrandr --output LVDS --set BACKLIGHT_CONTROL native", I can immediately adjust brightness with the function keys. With native, I am subject to what I believe above is being called the oscillation bug. This setup is non-functional. Also, with native, if I click the power manager icon, the power manager doesn't respond.

On the other hand, If i use the command "xrandr --output LVDS --set BACKLIGHT_CONTROL legacy", I have brightness control with the function keys, and I don't have the oscillation problem. Some other events do adjust brightness (and leave it that way) though, such as going to preferences of the power manager dims the display.

With either BACKLIGHT_CONTROL setting, I don't have to use the xbacklight command at all, and I don't have xbacklight installed.

At the moment, "BACKLIGHT_CONTROL legacy" is the only tolerable situation.