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["Christopher M. Penalver" <christopher.m.penalver@xxxxxxxxx>]

David Chatterton, Please execute the following command, as it will automatically gather debugging information, in a terminal:
apport-collect 1400155
When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

** Package changed: ubuntu-docs (Ubuntu) => linux (Ubuntu)

** Changed in: linux (Ubuntu)
   Importance: Undecided => Low

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https://bugs.launchpad.net/bugs/1400155

Title:
  inconsistent backlight brightness behaviour

Status in linux package in Ubuntu:
  Incomplete

Bug description:
  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

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