Sporadicly does not power off after will now halt message

[Borim]

I use Ubuntu 14.04 since it was released. Everything worked fine, but for about half a year after shutting down my pc does not power off the machine. It just freeze and stay active. The last message I see is "Will now halt"
This does not happen always, just from time to time. My impression is that this bug occur only if my PC runs for a longer time.

Usually I shutdown my pc with the command:
sudo shutdown -P now

Are any additional information needed?

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-79-generic 3.13.0-79.123
ProcVersionSignature: Ubuntu 3.13.0-79.123-generic 3.13.11-ckt33
Uname: Linux 3.13.0-79-generic x86_64
NonfreeKernelModules: wl tbs6982fe tbs6680fe tbs6923fe tbs6985se tbs6928se tbs6982se tbs6991fe tbs6618fe tbs6983fe tbs6922fe tbs6928fe tbs6991se tbs6290fe
ApportVersion: 2.14.1-0ubuntu3.19
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: mat 3124 F.... pulseaudio
 /dev/snd/controlC0: mat 3124 F.... pulseaudio
 /dev/snd/pcmC0D8p: mat 3124 F...m pulseaudio
CurrentDesktop: Unity
Date: Sun Mar 13 15:57:58 2016
InstallationDate: Installed on 2014-03-30 (714 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Daily amd64 (20140329)
MachineType: To Be Filled By O.E.M. To Be Filled By O.E.M.
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-79-generic root=UUID=afa0260e-e08d-416c-82a4-c9ae2e30d45b ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-79-generic N/A
 linux-backports-modules-3.13.0-79-generic N/A
 linux-firmware 1.127.20
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/11/2014
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P2.50
dmi.board.name: Z87E-ITX
dmi.board.vendor: ASRock
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP2.50:bd07/11/2014:svnToBeFilledByO.E.M.:pnToBeFilledByO.E.M.:pvrToBeFilledByO.E.M.:rvnASRock:rnZ87E-ITX:rvr:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.name: To Be Filled By O.E.M.
dmi.product.version: To Be Filled By O.E.M.
dmi.sys.vendor: To Be Filled By O.E.M.

[Brad Figg (brad-figg)]

This change was made by a bot.

[penalvch (penalvch)]

Borim, thank you for reporting this and helping make Ubuntu better.

In order to allow additional upstream developers to examine the issue, at your earliest convenience, could you please test the latest upstream kernel available from http://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D ? Please keep in mind the following:
1) The one to test is at the very top line at the top of the page (not the daily folder).
2) The release names are irrelevant.
3) The folder time stamps aren't indicative of when the kernel actually was released upstream.
4) Install instructions are available at https://wiki.ubuntu.com/Kernel/MainlineBuilds .

If testing on your main install would be inconvenient, one may:
1) Install Ubuntu to a different partition and then test this there.
2) Backup, or clone the primary install.

If the latest kernel did not allow you to test to the issue (ex. you couldn't boot into the OS) please make a comment in your report about this, and continue to test the next most recent kernel version until you can test to the issue. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this issue is fixed in the mainline kernel, please add the following tags by clicking on the yellow circle with a black pencil icon, next to the word Tags, located at the bottom of the report description:
kernel-fixed-upstream
kernel-fixed-upstream-X.Y-rcZ

Where X, and Y are the first two numbers of the kernel version, and Z is the release candidate number if it exists.

If the mainline kernel does not fix the issue, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-X.Y-rcZ

Please note, an error to install the kernel does not fit the criteria of kernel-bug-exists-upstream.

Also, you don't need to apport-collect further unless specifically requested to do so.

Once testing of the latest upstream kernel is complete, please mark this report Status Confirmed. Please let us know your results.

Thank you for your understanding.

[Borim (borim)]

The bug also exists in linux kernel 4.5, tested with linux-image-4.5.0-040500-generic_4.5.0-040500.201603140130_amd64

[penalvch (penalvch)]

Borim, to clarify, did this issue not occur in a release prior to 14.04?

[Borim (borim)]

The issue did not occur before 14.04, also the first version of 14.04 were also bug free.
The bug annoys me for ca. half till one year.

[penalvch (penalvch)]

Borim, the next step is to fully commit bisect from kernel 3.13.0-24.46 to 3.13.0-79.123 in order to identify the last good kernel commit, followed immediately by the first bad one. This will allow for a more expedited analysis of the root cause of your issue. Could you please do this following https://wiki.ubuntu.com/Kernel/KernelBisection ?

Please note, finding adjacent kernel versions is not fully commit bisecting.

After the offending commit (not kernel version) has been identified, then please mark this report Status Confirmed.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs

[Launchpad Janitor (janitor)]

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