wifi constantly gets disconnected = wpa_supplicant[...]: wlan0: CTRL-EVENT-DISCONNECTED

[Vish]

The wifi connection repeatedly gets disconnected.
At times, the connection disconnects and does not reconnect automatically. Disabling the wifi and reenabling it or either choosing the network are the only way to reconnect.
If the net is being used, while streaming videos or other downloads, the disconnects are more frequent.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-36-generic 3.13.0-36.63
ProcVersionSignature: Ubuntu 3.13.0-36.63-generic 3.13.11.6
Uname: Linux 3.13.0-36-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.4
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC2: vish 1869 F.... pulseaudio
 /dev/snd/controlC0: vish 1869 F.... pulseaudio
 /dev/snd/controlC1: vish 1869 F.... pulseaudio
CurrentDesktop: Unity
Date: Tue Oct 7 00:56:22 2014
HibernationDevice: RESUME=UUID=c1bae3ed-625a-4557-b3eb-e4c53d61652e
InstallationDate: Installed on 2014-05-17 (142 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
MachineType: Dell Inc. Inspiron 3847
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-36-generic.efi.signed root=UUID=da145a9d-65f5-443b-b68a-c42fc17a50c2 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-36-generic N/A
 linux-backports-modules-3.13.0-36-generic N/A
 linux-firmware 1.127.7
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/03/2014
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A04
dmi.board.name: 088DT1
dmi.board.vendor: Dell Inc.
dmi.board.version: A01
dmi.chassis.type: 3
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA04:bd04/03/2014:svnDellInc.:pnInspiron3847:pvr:rvnDellInc.:rn088DT1:rvrA01:cvnDellInc.:ct3:cvr:
dmi.product.name: Inspiron 3847
dmi.sys.vendor: Dell Inc.

[Brad Figg (brad-figg)]

This change was made by a bot.

[penalvch (penalvch)]

Vish, 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 (not the daily folder) following https://wiki.ubuntu.com/KernelMainlineBuilds ? It will allow additional upstream developers to examine 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-3.17

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.

[Vish (vish)]

Syslog where connection does not reconnect and the network is missing from the dropdown list. Only Diabling/Enabling the WiFi works.

[Vish (vish)]

Seth,
I believe this is similar to Bug #1293569 : iwlwifi-7260-8.ucode causes network disconnections problems.
Opened a new bug report and subscribed you here as per your comments. PLease advise.

[Vish (vish)]

Christopher,
I'm testing with the latest kernel, but I have encountered this error:

Setting up linux-headers-3.14.4-031404 (3.14.4-031404.201405130853) ...
dpkg: dependency problems prevent configuration of linux-headers-3.14.4-031404-generic:
 linux-headers-3.14.4-031404-generic depends on linux-headers-3.14.4-031404.

dpkg: error processing package linux-headers-3.14.4-031404-generic (--install):
 dependency problems - leaving unconfigured

[Seth Forshee (sforshee)]

Vish: You probably don't need any headers packages, only the linux-image package for your architecture. If you do need the headers (e.g. for dkms modules) then you need to make sure you grab both the linux-header*_all.deb file in addition to the one for your architecture.

However I'd suggest starting with 3.17 instead of 3.14. If it's not fixed in 3.17 then it likely isn't fixed in 3.14 either, and if it is fixed in 3.17 we can start hunting for the fix. You can get the 3.17 build from here:

http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.17-utopic/

(Note that it doesn't matter if it says trusty or utopic in the name, that simply describes which version the configuration and packaging were based on. You can easily install -utopic mainline builds on trusty.)

[Vish (vish)]

I've tested with the following kernels and it works much better.
linux-image-3.15.10-031510-generic
linux-image-3.16.4-031604-generic
linux-image-3.17.0-031700-generic

-16 and -17, I could not test for more than a day since I had segfaults.
-15 I've been running for 2 and a half days and the issue is not even noticible.

The only reason I am saying 'not noticible' is because, I did notice the same disconnect messages in the syslogs a couple of times but I did not have to reconnect to the network manually.?field.comment=I've tested with the following kernels and it works much better.
linux-image-3.15.10-031510-generic
linux-image-3.16.4-031604-generic
linux-image-3.17.0-031700-generic

-16 and -17, I could not test for more than a day since I had segfaults.
-15 I've been running for 2 and a half days and the issue is not even noticible.

The only reason I am saying 'not noticible' is because, I did notice the same disconnect messages in the syslogs a couple of times but I did not have to reconnect to the network manually.

[Vish (vish)]

I just noticed a disconnect today where I had to manually reconnect to the network.
But this disconnect was for a Reason: 6=CLASS2_FRAME_FROM_NONAUTH_STA

My previous disconnects were mainly for a reason 4, should this be a seperate bug?

[penalvch (penalvch)]

Vish, would 3.18-rc3 provide better results than 3.15?

[penalvch (penalvch)]

Vish, as well, as per http://www.dell.com/support/home/us/en/04/product-support/product/inspiron-3847-desktop/drivers an update to your BIOS is available (A05). If you update to this following https://help.ubuntu.com/community/BIOSUpdate does it change anything? If it doesn't, could you please both specify what happened, and provide the output of the following terminal command:
sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date

Thank you for your understanding.

[Vish (vish)]

I have been using Kernel 3.18.0-031800rc4-generic #201411091835 , for 8 days with no issues

[penalvch (penalvch)]

Vish, the next step is to fully reverse commit bisect from kernel 3.15 to 3.18-rc4 in order to identify the last bad commit, followed immediately by the first good one. Once this commit has been identified, then it may be reviewed as a candidate for backporting into your release. Could you please do this following https://wiki.ubuntu.com/Kernel/KernelBisection#How_do_I_reverse_bisect_the_upstream_kernel.3F ? Please note, finding adjacent kernel versions is not fully commit bisecting.

Thank you for your understanding.

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

[Paul Abrahams (abrahams)]

I'm running Kubuntu 14.04 and I get occasional network disconnections. The interval between them varies widely. I have kernel 3.19.0-42-generic installed, according to uname. There are many reports of this problem, as a google search will reveal. Also search on "wpa_supplicant CTRL-EVENT-DISCONNECTED reason=6". My router is a TP-Link TL-WR841N.