kernel-packages team mailing list archive

[Alan Pater <alan.pater@xxxxxxxxx>]

Looks like you have run into the infamous  CPU frequency issue.

http://www.thinkwiki.org/wiki/Problem_with_CPU_frequency_scaling

Solution is to make sure you are running with high quality AC power.

Workaround is to edit /etc/default/grub

Find the following line and add processor.ignore_ppc=1
so it looks like this:

  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash processor.ignore_ppc=1"

then	
  sudo update-grub && sudo reboot.

Have a nice day.

-- 
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/1246793

Title:
  Battery charging slows down laptop

Status in “linux” package in Ubuntu:
  Incomplete

Bug description:
  Following up on Bug #962712 which was marked as invalid, instead of
  fixed (gee, thanks...) I'm using Ubuntu 13.10 and this still happening
  pretty badly.

  Steps to reproduce:

  1) Unplug laptop, plug-in second monitor, drain battery until OS warns user and asks her to plugin laptop
  2) Plugin laptop

  Expected: Laptop works normally
  Actual: Laptop slows down severely.

  -=-=-

  Drilling down, run `cpufreq-info`

  Expected:
  driver: acpi-cpufreq [...]
  current policy: frequency should be within 800 MHz and 2.80 GHz.

  Actual: 
  driver: acpi-cpufreq [...]
  current policy: frequency should be within 800 MHz and 800 MHz

  -=-=-

  Drilling down, this is known, lingering problem, and is not "invalid",
  please triage instead of sweeping under the rug

   * http://ubuntuforums.org/showthread.php?t=1921292
   * http://askubuntu.com/questions/186387/laptop-slows-down-while-charging-battery
   * http://bit.ly/17vgUO0
   * ...

  -=-=-

  Thank you for your consideration.
  --- 
  ApportVersion: 2.12.5-0ubuntu2.1
  Architecture: amd64
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC0:  dac514     2414 F.... pulseaudio
  DistroRelease: Ubuntu 13.10
  EcryptfsInUse: Yes
  HibernationDevice: RESUME=UUID=b95f5ff9-5665-42f8-8b10-f2ae3ca2411f
  InstallationDate: Installed on 2012-06-12 (505 days ago)
  InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
  MachineType: LENOVO 4286CTO
  MarkForUpload: True
  Package: linux (not installed)
  ProcFB: 0 inteldrmfb
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.11.0-12-generic root=UUID=59641606-e542-4c74-8a31-08c66bfae100 ro quiet splash vt.handoff=7
  ProcVersionSignature: Ubuntu 3.11.0-12.19-generic 3.11.3
  RelatedPackageVersions:
   linux-restricted-modules-3.11.0-12-generic N/A
   linux-backports-modules-3.11.0-12-generic  N/A
   linux-firmware                             1.116
  RfKill:
   0: phy0: Wireless LAN
   	Soft blocked: no
   	Hard blocked: no
  Tags:  saucy
  Uname: Linux 3.11.0-12-generic x86_64
  UpgradeStatus: Upgraded to saucy on 2013-10-08 (23 days ago)
  UserGroups: adm audio cdrom dip lpadmin plugdev sambashare sudo
  WifiSyslog:
   
  dmi.bios.date: 07/18/2013
  dmi.bios.vendor: LENOVO
  dmi.bios.version: 8DET69WW (1.39 )
  dmi.board.asset.tag: Not Available
  dmi.board.name: 4286CTO
  dmi.board.vendor: LENOVO
  dmi.board.version: Not Available
  dmi.chassis.asset.tag: No Asset Information
  dmi.chassis.type: 10
  dmi.chassis.vendor: LENOVO
  dmi.chassis.version: Not Available
  dmi.modalias: dmi:bvnLENOVO:bvr8DET69WW(1.39):bd07/18/2013:svnLENOVO:pn4286CTO:pvrThinkPadX220:rvnLENOVO:rn4286CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
  dmi.product.name: 4286CTO
  dmi.product.version: ThinkPad X220
  dmi.sys.vendor: LENOVO

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