I noticed that running manually
xrandr --output LVDS1 --set BACKLIGHT 0
makes the screen brightness maximum.

If I boot without acpi=off and run the xrandr-command, nothing happends.
None of the Fn-key work either as acpi is on, so I guess the ACPI is
broken.

To make the screen as dim as possible, run
xrandr --output LVDS1 --set BACKLIGHT  2948310

Maybe the range should be the other way around, 0 as minimum lightness?

$ xrandr --prop
Screen 0: minimum 320 x 200, current 1366 x 768, maximum 8192 x 8192
LVDS1 connected 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 
193mm
        EDID:
                00ffffffffffff000daf991500000000
                07140103802213780a3d9594564f8e28
                26505400000001010101010101010101
                0101010101017a1d56d250001e303c28
                360058c110000018000000fe004e3135
                3642332d4c30420a2020000000fe0043
                4d4f0a202020202020202020000000fe
                004e31353642332d4c30420a20200048
        BACKLIGHT: 1 (0x00000001)       range:  (0,2948310)
        Backlight: 1 (0x00000001)       range:  (0,2948310)
        scaling mode:   Full aspect
                supported: None         Full         Center       Full aspect 
   1366x768       60.0*+
   1360x768       59.8     60.0  
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  

As a workaround I tried to add
xrandr --output LVDS1 --set BACKLIGHT 0 -display :0
to /etc/rc.local but it does not work (error says cookie mismatch).

A less optimal workaround I added the command to the Gnome session, but
LDM starts out dimmed, so the sole user of the laptop has to enter their
password blindly (screen is to dark to see almost anything).

-- 
You received this bug notification because you are a member of Ubuntu-X,
which is subscribed to xorg in Ubuntu.
https://bugs.launchpad.net/bugs/910536

Title:
  Screen too dark, no backlight, unusable X

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/910536/+subscriptions

_______________________________________________
Mailing list: https://launchpad.net/~ubuntu-x-swat
Post to     : ubuntu-x-swat@lists.launchpad.net
Unsubscribe : https://launchpad.net/~ubuntu-x-swat
More help   : https://help.launchpad.net/ListHelp

Reply via email to