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[Shriramana Sharma <1255428@xxxxxxxxxxxxxxxxxx>]

Hello Christopher. Sorry for the delay. I am having problems downloading
the daily images but I trusted with Alpha 2, and the bug persists there.

And I did not test the mainline kernels since as noted earlier, even
with the Saucy kernel, if we directly write to
/sys/class/backlight/intel_backlight/brightness then the brightness does
change, so even the default Saucy kernel is clearly capable of telling
the hardware to change its brightness.

The problem lies probably in that the GUI as in the power management
applet popup and the keyboard hook which should handle the pressing of
the physical brightness keys on keyboard are somehow not able to modify
the /sys/class/backlight/* file or so.

With the existing setup, I have having to sudo to modify the
/sys/class/* file, so perhaps the process running the GUI popup or the
keyboard hook does not have the relevant permissions to change the
/sys/class/* file.

-- 
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https://bugs.launchpad.net/bugs/1255428

Title:
  LCD brightness control keys and widget do not work on Intel Graphics
  on Saucy

Status in “linux” package in Ubuntu:
  Confirmed

Bug description:
  After upgrading to Saucy, on my Lenovo IdeaPad Z570 with Intel HD
  Graphics 3000, it is no longer possible to control the LCD brightness
  using the hardware brightness control keys. Likewise for the KDE power
  management settings or the battery icon on my Kubuntu Plasma tray. (I
  don't use GNOME/Unity.) Until Raring I did not have this problem.

  There is a workaround available from
  http://askubuntu.com/questions/362894/changing-the-brightness-stopped-
  working-in-13-10-saucy-salamander i.e. doing the following command on
  a terminal:

  echo 150 | sudo tee /sys/class/backlight/intel_backlight/brightness

  where 150 is on the scale of 0 to whatever is given within
  /sys/class/backlight/intel_backlight/max_brightness.

  Based on this I wrote a GUI which however needs to be run using
  sudo/kdesudo/gksudo. I have attached it.

  Bug #1241745 also relates to the same problem on Saucy but apparently relates to an NVidia driver and I was asked to track this as a separate bug https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1241745/comments/17
  --- 
  ApportVersion: 2.12.5-0ubuntu2.1
  Architecture: amd64
  DistroRelease: Ubuntu 13.10
  InstallationDate: Installed on 2013-10-19 (38 days ago)
  InstallationMedia: Kubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
  MarkForUpload: True
  Package: xserver-xorg-video-intel 2:2.99.904-0ubuntu2
  PackageArchitecture: amd64
  ProcVersionSignature: Ubuntu 3.11.0-13.20-generic 3.11.6
  Tags:  saucy
  Uname: Linux 3.11.0-13-generic x86_64
  UpgradeStatus: No upgrade log present (probably fresh install)
  UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo

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