Public bug reported: This bug refers to a Dell XPS13-9333 running Ubuntu 14.10.
I discovered a workaround to prevent the screen starting with full brightness. The reference to the workaround advice is: http://ubuntuhandbook.org/index.php/2014/04/save-screen-brightness-settings-in-ubuntu-14-04/ There is a folder sys/class/backlight/intel_backlight/ containing a number of files such as brightness, actual_brightness and max_brightness. When using Fn-F4 & F5 to control the screen backlight, the two files: brightness and actual_brightness respond by changing there contents to a number which is a proportion of the contents of max_brightness (937). The workaround was to include the line: echo 569 > /sys/class/backlight/intel_backlight/brightness at the end of the file: /etc/rc.local using gedit (where 569 is a value noted for a typically comfortable level of backlight). This works when doing a restart but, when logging back in after logging out, the backlight comes on at maximum brightness. This particular laptop has a front-facing webcam fitted. Its function can be confirmed by running the Cheese webcam Booth. It would be a vast improvement if the ambient brightness could be sensed by the webcam and used to adjust the backlight brightness. Auto brightness could be selected or not by a tick box in the Brightness & Lock section of System Settings. Similarly, a tick box might also be provided to enable saving of the backlight brightness when shutting down or logging off ** Affects: ubuntu-docs (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1400155 Title: inconsistent backlight brightness behaviour To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-docs/+bug/1400155/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
