Ubuntu
xserver-xorg-video-intel package

  1. Bug #686216
  2. Comment #4

Comment 4 for bug 686216

Revision history for this message
chreko (chreko) wrote : Re: Brightness is all the way down at login screen on HP Pavilion dm4

I am not sure if the following is a relevant workaround for you, but it is worth checking it:

See section "BRIGHTNESS CONTROL OF THE DISPLAY" at http://www.andreas-demmer.de/en/2010/07/18/testbericht-linux-auf-dem-hp-envy-14/

In particular: "[...] After having done this, there should exist a file named /sys/class/backlight/i915/brightness. If you write values between 0 and 9 into it, the brightness of the screen changes immediately:

echo -n5 > /sys/class/backlight/i915/brightness

[...]"