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[Bug 1579917] Re: Skylake processor never reaches low power states on X1 Carbon gen 4 with NVMe drive


** Changed in: linux (Ubuntu)
     Assignee: (unassigned) => Colin Ian King (colin-king)

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  Skylake processor never reaches low power states on X1 Carbon gen 4
  with NVMe drive

Status in linux package in Ubuntu:

Bug description:
  1. Find a skylake machine. - in my case Lenovo x1 carbon gen 4. In my case with an NVME drive.
  2. run powertop, and switch to idle stats tab
  3. do nothing. *(as in let the machine idle till the cores regularly reach low power states.
  4. Watch the watts fly.  On my  machine the package never gets into any power state other than PC2.

  Expected results: PC3-PC10 power states should all show some usage.

  I also tried the mainline build of 4.6-rc7 with no benefits.

  Public conversations about the issue

  As far as I can tell having the nvme drive is part of the overall
  problem here.  Please keep this case to skylake + nvme.  Skylake +
  sata appears to have a number of fixes in the 4.6 and newer kernels
  that enable some of the higher sleep states, but I have not tested
  with a sata drive.  Those fixes as of testing 4.6-rc7 do not resolve
  this issue with users who have nvme drives.

  ProblemType: Bug
  DistroRelease: Ubuntu 16.04
  Package: linux-image-4.4.0-22-generic 4.4.0-22.39
  ProcVersionSignature: Ubuntu 4.4.0-22.39-generic 4.4.8
  Uname: Linux 4.4.0-22-generic x86_64
  ApportVersion: 2.20.1-0ubuntu2
  Architecture: amd64
   /dev/snd/controlC0:  chiluk     3139 F.... pulseaudio
  CurrentDesktop: Unity
  Date: Mon May  9 15:55:03 2016
  HibernationDevice: RESUME=UUID=4f4ea88e-642e-4be5-bdf0-bbc7f47f5628
  InstallationDate: Installed on 2016-04-25 (14 days ago)
  InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
   Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
   Bus 001 Device 003: ID 04f2:b531 Chicony Electronics Co., Ltd 
   Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
  MachineType: LENOVO 20FBCTO1WW
  ProcFB: 0 inteldrmfb
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-22-generic.efi.signed root=UUID=249f91bb-7789-41cc-9cc0-8ba25d7f55bb ro quiet splash pcie_aspm=force vt.handoff=7
   linux-restricted-modules-4.4.0-22-generic N/A
   linux-backports-modules-4.4.0-22-generic  N/A
   linux-firmware                            1.157
  SourcePackage: linux
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 03/15/2016
  dmi.bios.vendor: LENOVO
  dmi.bios.version: N1FET37W (1.11 )
  dmi.board.asset.tag: Not Available
  dmi.board.name: 20FBCTO1WW
  dmi.board.vendor: LENOVO
  dmi.board.version: SDK0J40709 WIN
  dmi.chassis.asset.tag: No Asset Information
  dmi.chassis.type: 10
  dmi.chassis.vendor: LENOVO
  dmi.chassis.version: None
  dmi.modalias: dmi:bvnLENOVO:bvrN1FET37W(1.11):bd03/15/2016:svnLENOVO:pn20FBCTO1WW:pvrThinkPadX1Carbon4th:rvnLENOVO:rn20FBCTO1WW:rvrSDK0J40709WIN:cvnLENOVO:ct10:cvrNone:
  dmi.product.name: 20FBCTO1WW
  dmi.product.version: ThinkPad X1 Carbon 4th
  dmi.sys.vendor: LENOVO

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