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[Launchpad Bug Tracker <1433410@xxxxxxxxxxxxxxxxxx>]

[Expired for linux (Ubuntu) because there has been no activity for 60
days.]

** Changed in: linux (Ubuntu)
       Status: Incomplete => Expired

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https://bugs.launchpad.net/bugs/1433410

Title:
  Auto backlight control. Modprobe samsung_laptop returns "ERROR...No
  such device" on Samsung XE700T

Status in linux package in Ubuntu:
  Expired

Bug description:
  Please see the full description on:
  http://ubuntuforums.org/showthread.php?t=2216224&page=2

  I posted on ubuntu forum after trying numerous ineffective solutions
  to a backlight auto-dimming issue. After running through a
  troubleshooting process which is described on the page linked above, I
  was advised by Toz to submit a kernel bug.

  sudo dmidecode -s system-manufacturer
  SAMSUNG ELECTRONICS CO., LTD.
  sudo dmidecode -s system-product-name
  700T1C
  sudo dmidecode -s system-version
  P10AAT

  sudo modprobe samsung_laptop
  modprobe: ERROR: could not insert 'samsung_laptop': No such device

  cat /proc/cmdline
  BOOT_IMAGE=/vmlinuz-3.16.0-31-generic.efi.signed root=/dev/mapper/ubuntu--vg-root ro acpi_osi=Linux quiet splash vt.handoff=7

  lsb_release -rd
  Description:	Ubuntu 14.04.2 LTS
  Release:	14.04

  Summary:
  I can't control the brightness from my settings or by manually changing the values in ../intel_backlight/brightness.
  My auto brightness seems to have a mind of its own and unfortunately for me I can't fix it with the "acpi_osi=" trick. Since the auto brightness flickers up and down every few seconds, its so frustrating that I can barely use my tablet. I tried my best to fix in the last 4 days since I re-installed Ubuntu, but regardless of what I tried, I simply can't stabilize it, nevermind control it. At this state I would be delighted if I could just set it to one value at boot.

  After running a few commands as advised by Toz, the flickering seems
  to have stopped while the tablet is plugged in, but while the settings
  value shows my screen at max brightness, its definitely not as bright
  as in Windows. (and I definitely don't want to use Windows as my main
  OS).

  I would like to be able to control the brightness manually in the
  power settings or by setting it at boot in rc.local.

  PS: btw the controls for gyro, accelometer and rotation don't seem to
  be functional in Ubuntu, even if they show up in lsmod as loaded.
  Could these be because of the missing samsung_laptop module?

  I hope this helps. If you require further info, please get in touch.
  Thanks!

  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: linux-image-3.16.0-31-generic 3.16.0-31.43~14.04.1
  ProcVersionSignature: Ubuntu 3.16.0-31.43~14.04.1-generic 3.16.7-ckt5
  Uname: Linux 3.16.0-31-generic x86_64
  ApportVersion: 2.14.1-0ubuntu3.7
  Architecture: amd64
  CurrentDesktop: Unity
  Date: Wed Mar 18 03:05:42 2015
  EcryptfsInUse: Yes
  InstallationDate: Installed on 2015-03-11 (6 days ago)
  InstallationMedia: Ubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
  SourcePackage: linux-lts-utopic
  UpgradeStatus: No upgrade log present (probably fresh install)

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