06-02-2012 04:31 PM - edited 06-02-2012 04:37 PM
I have a x220, 4290ch9 and I've installed ubuntu 12.04 on it. One problem, the system can't remember the screen's brightness. Everytime when I reboot the PC, the brightness is reset to minimum, and I have to turn up the brightness manually (with Fn+Home).
I have added the following line into the file /etc/rc.local: echo 12 > /sys/class/backlight/acpi_video0/brightness
Ok, I get good brightness when the ubuntu logo appears, but once I get into the login screen, the brightness is still reset to zero. It looks like something is keeping resetting the brightness of my screen.
I'm sure that rc.local is executed, since if I add "mkdir /home/myhome/toto" in it, it do create a new folder named toto in my home.
Even in Windows 7, I have noticed the same thing, when Windows 7 logo appears, I have the minimum brightness, but once the login screen shows up, the brightness gets back to normal. In ubuntu, it's the inverse.
Does anyone have a solution ?