I tried the same while blacklisting nouveau driver in grub: $ cat /proc/cmdline BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash modprobe.blacklist=nouveau ---
This time, I have "acpi_video0" in /sys/class/backlight, but the result is the same. The screen is very dark. /sys/class/backlight/acpi_video0/brightness is 100 by default. I can modify this value with $ sudo su # echo 60 > /sys/class/backlight/acpi_video0/brightness and the brightness actually changes to something even darker. If I try to set it over 100, I get: write error: Invalid argument -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1821882 Title: Screen is very dark and brightness cannot be adjusted To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1821882/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
