Ubuntu continuously suspends, resumes, suspends, resumes, when battery low

[NoBugs!]

I've had this problem happen at least once before - when Ubuntu sees battery is critically low, it suspends, but immediately starts up again, shows login screen, suspends, starts up to the login screen, suspends. Even if you log in quickly and click "suspend", or shut the laptop, it still suspends and resumes again and again.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-39-generic 3.13.0-39.66
ProcVersionSignature: Ubuntu 3.13.0-39.66-generic 3.13.11.8
Uname: Linux 3.13.0-39-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: luke 3091 F.... pulseaudio
CurrentDesktop: Unity
Date: Fri Nov 21 17:58:36 2014
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=136d3aa0-26df-4f6e-8eb2-9ade44134645
InstallationDate: Installed on 2013-11-23 (363 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
MachineType: Dell Inc. XPS L521X
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-39-generic.efi.signed root=UUID=8e997c12-0ee0-422b-a7e4-a7cb0a74f38f ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-39-generic N/A
 linux-backports-modules-3.13.0-39-generic N/A
 linux-firmware 1.127.8
SourcePackage: linux
UpgradeStatus: Upgraded to trusty on 2014-04-19 (216 days ago)
dmi.bios.date: 12/17/2013
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A16
dmi.board.name: 0C5Y96
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: A16
dmi.modalias: dmi:bvnDellInc.:bvrA16:bd12/17/2013:svnDellInc.:pnXPSL521X:pvrA16:rvnDellInc.:rn0C5Y96:rvrA00:cvnDellInc.:ct8:cvrA16:
dmi.product.name: XPS L521X
dmi.product.version: A16
dmi.sys.vendor: Dell Inc.

[Brad Figg (brad-figg)]

This change was made by a bot.

[penalvch (penalvch)]

NoBugs!, thank you for reporting this and helping make Ubuntu better. Could you please test the latest upstream kernel available from the very top line at the top of the page (the release names are irrelevant for testing, and please do not test the daily folder) following https://wiki.ubuntu.com/KernelMainlineBuilds ? It will allow additional upstream developers to examine the issue.

If the test 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 bug is fixed in the mainline kernel, please add the following tags:
kernel-fixed-upstream
kernel-fixed-upstream-VERSION-NUMBER

where VERSION-NUMBER is the version number of the kernel you tested exactly shown as:
kernel-fixed-upstream-3.18-rc4

This can be done by clicking on the yellow circle with a black pencil icon next to the word Tags located at the bottom of the bug description.

If the mainline kernel does not fix this bug, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-VERSION-NUMBER

Once testing of the upstream kernel is complete, please mark this bug's Status as Confirmed. Please let us know your results. Thank you for your understanding.

[NoBugs! (luke32j)]

I updated with the latest kernel .deb, uname -a gives me:

Linux linuxlaptop 3.18.0-031800rc5-generic #201411162035 SMP Mon Nov 17 01:36:34 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

I still see the problem. When it suspends at low battery, it immediately starts up again, but doesn't go into an infinite loop of suspend-resumes. When I shut it I hear it suspend, disk powers down, then it powers up.

[NoBugs! (luke32j)]

This might have happened in 13.10, I don't remember.

[NoBugs! (luke32j)]

I tested an old 13.04 disk ( I don't know if I have a 13.10 around), and it gave numerious Unity/Compiz crash warnings, and on low-battery it did try to shut down and immediatly came back up like in Trusty.

[penalvch (penalvch)]

NoBugs!, could you please test the latest mainline kernel 3.18-rc6 and advise to the results?

[NoBugs! (luke32j)]

Just tried 3.18.0-031800rc6-generic 64-bit, it tries to suspend, and just starts up again to lock screen. No infinite loop, at least.

[penalvch (penalvch)]

NoBugs!, could you please provide the missing information following https://wiki.ubuntu.com/DebuggingKernelSuspend ?

[NoBugs! (luke32j)]

After low batt and resume, cat /proc/acpi/wakeup > wakeup gives this

[Launchpad Janitor (janitor)]

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

[NoBugs! (luke32j)]

The same happens in 3.19.0-031900rc7-generic

Does this bug need to go to the Linux Kernel tracker?

[penalvch (penalvch)]

NoBugs!, with 3.19-rc7 could you please provide the two missing action items following https://wiki.ubuntu.com/DebuggingKernelSuspend ?

[NoBugs! (luke32j)]

Yes, FYI this has still not been fixed and it still happens on 4.2.0-42-generic

In fact when I deliberately hit suspend action from top right it starts up again and eats up battery.