Same problem here. I cannot adjust the brightness using the GUI controls or the intel_backlight controls in /sys. The following action has (almost) no effect to the brightness or the value exposed in "actual_brightness" in /sys/class/backlight/intel_backlight:
echo $value /sys/class/backlight/intel_backlight/brightness Example no change by running the following commands as root: echo 1 > /sys/class/backlight/intel_backlight/brightness echo `cat /sys/class/backlight/intel_backlight/max_brightness` > /sys/class/backlight/intel_backlight/brightness The only difference that can be observed is when writing 0 to the file: echo 0 > /sys/class/backlight/intel_backlight/brightness This turns off the display. The bug does not exist in linux-image-5.4.0-21-generic, so installing the standard non-oem kernel is a workaround to the bug. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1871330 Title: Dell XPS 13 (7390) brightness is not adjustable with recent kernel update To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-oem-5.4/+bug/1871330/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
