kernel-packages team mailing list archive

[Luís de Sousa <1347539@xxxxxxxxxxxxxxxxxx>]

I managed to install and run the mainline kernel (3.17). With it the
battery discharge rate is dramatically down, about half of what it is
with kernel 3.13 (~ 15W), but still above what it was with Ubuntu 12.04.
Also, with kernel 3.17 it seems the automatic screen dimming is not
working.

Cheers.

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

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1347539

Title:
  Abnormally high battery discharge rate on Lenovo T420

Status in “linux” package in Ubuntu:
  Confirmed

Bug description:
  I have upgraded from12.04 to 14.04 on a Lenovo T420 laptop
  (Corei7-2620M CPU @ 2.70GHz × 4 + Sandybridge Mobile). Whereas with
  12.04 the battery discharge rate would stay somewhere between 10 - 12
  W/h, with 14.04 it remains persistently over 30 W/h.

  The discharge rate came closer to normal after an upgrade by late May.
  But last week, apparently after an upgrade to linux-headers-generic,
  the abnormally high discharge rate is back.

  This thread at AskUbuntu details what I have tried (unsuccessfully) to
  identify the cause of this problem:

  http://askubuntu.com/questions/461620/ubuntu-14-04-draining-laptop-
  battery-quicker-than-in-12-04-1-hour-versus-4-hou

  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: ubuntu-release-upgrader-core 1:0.220.2
  ProcVersionSignature: Ubuntu 3.13.0-32.57-generic 3.13.11.4
  Uname: Linux 3.13.0-32-generic x86_64
  ApportVersion: 2.14.1-0ubuntu3.2
  Architecture: amd64
  CrashDB: ubuntu
  CurrentDesktop: Unity
  Date: Wed Jul 23 11:15:26 2014
  InstallationDate: Installed on 2011-07-22 (1096 days ago)
  InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
  PackageArchitecture: all
  SourcePackage: ubuntu-release-upgrader
  Symptom: release-upgrade
  UpgradeStatus: Upgraded to trusty on 2014-05-02 (81 days ago)
  VarLogDistupgradeTermlog:

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1347539/+subscriptions