Wifi connection issues

[Marvin Scholz]

1) Ubuntu Version: 15.04 (Vivid Vervet)
2) Kernel Version: 3.19.0-12-generic

Wireless: Intel Wireless 7265 (on Thinkpad X250)

3) I expect Wifi to work as expected without connection drops.

4) I am experiencing sudden connection drops, which means I am not able to connect to anything after a certain time and it seems that it only happens after certain amount of data has be downloaded. Although the Wifi still appears as connected, it behaves like it isn't.

Other:
When I am booting with Kernel 3.16.0-23-generic I do not experience any Wifi connection problems at all.

(I am not sure if this bugreport is fine, as this is the first time I am reporting a bug here, I will be happy to do improvements to the report if I did anything wrong or provide as much data as possible upon request.)
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ApportVersion: 2.17-0ubuntu1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: epirat 1708 F.... pulseaudio
 /dev/snd/controlC0: epirat 1708 F.... pulseaudio
CurrentDesktop: Unity
DistroRelease: Ubuntu 15.04
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-04-09 (6 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
MachineType: LENOVO 20CLS0JA00
Package: linux (not installed)
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.19.0-12-generic root=UUID=28d14754-0ce2-45a9-a1aa-068caaab54d0 ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 3.19.0-12.12-generic 3.19.3
RelatedPackageVersions:
 linux-restricted-modules-3.19.0-12-generic N/A
 linux-backports-modules-3.19.0-12-generic N/A
 linux-firmware 1.143
Tags: vivid
Uname: Linux 3.19.0-12-generic x86_64
UpgradeStatus: Upgraded to vivid on 2015-04-09 (6 days ago)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
_MarkForUpload: True
dmi.bios.date: 01/23/2015
dmi.bios.vendor: LENOVO
dmi.bios.version: N10ET28W (1.05 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20CLS0JA00
dmi.board.vendor: LENOVO
dmi.board.version: SDK0E50510 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvrN10ET28W(1.05):bd01/23/2015:svnLENOVO:pn20CLS0JA00:pvrThinkPadX250:rvnLENOVO:rn20CLS0JA00:rvrSDK0E50510WIN:cvnLENOVO:ct10:cvrNone:
dmi.product.name: 20CLS0JA00
dmi.product.version: ThinkPad X250
dmi.sys.vendor: LENOVO

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1444766/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

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[Marvin Scholz (epirat07)]

Re #1: I can't find a package for the kernel when searching for it.

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.0 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.0-vivid/

[Marvin Scholz (epirat07)]

Test with upstream kernel 4.0 done

[Marvin Scholz (epirat07)]

Just updated, the bug is still present.

Output of `sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date`:

    /dev/mem: No such file or directory

[Christopher M. Penalver (penalvch)]

Marvin Scholz, the next step is to fully commit bisect from kernel 3.16 to 3.19 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.

Thank you for your understanding.

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

[Marvin Scholz (epirat07)]

Without any hint which commit(s) could be affected, this can take ages, as the problem is very hard to reproduce… I would need to test each commit for hours until I can say if the bug is present or not…

[Marvin Scholz (epirat07)]

If I have time I will do bisect next week, already did some more testing, it still works up to 3.18.6

[Marvin Scholz (epirat07)]

I now tested with 3.18.11 and I am experiencing Wifi issues, but they behave different than my current Wifi issues, so I have no Idea how to proceed… Please give me indications what to do?

(The issue there is that after a while downloading large (1GB+) files, I get a popup that there was an internal error. I tried to click on report but the bugreport tool refused to do so, telling me this kernel looks like an upstream kernel version and I can't report bugs for it)

[Marvin Scholz (epirat07)]

I meant "mainline" not "upstream"

[Christopher M. Penalver (penalvch)]

Marvin Scholz, mainline and upstream are one in the same.

Despite this, I would just mark 3.18.11 as bad, and continue on the bisection.

[Marvin Scholz (epirat07)]

I have now clearly identified a working and non-working version and tried to start the full commit bisect, but I am unable to follow the guide in the wiki as it points me to change the version number in the debian.master/changelog file. Unfortunately, there is no such file.

Another question: The working version I identified was 3.18.6 but I can't find a tag for this version in the git repo, why is that? (I just used Ubuntu-3.18.0-14.15 as I was unsure what to do... Please note I never worked with kernel sourcecode before so this is all quite new to me, sorry if I ask basic questions)

[Joseph Salisbury (jsalisbury)]

Just to confirm 3.18.6 is the last good version and 3.18.7 is the first bad version? If so, I can start a bisect between these two versions.

[Marvin Scholz (epirat07)]

I've tested v3.18.14-vivid and it works for me, the first 3.19 version does not.

[Joseph Salisbury (jsalisbury)]

Can you test the following two kernels and confirm 3.18.6 is good and 3.18.7 is bad? They can be downloaded from:

v3.18.6: http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.18.6-vivid/

v3.18.7: http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.18.7-vivid/

[Tasev Nikola (tasev-stefanoska)]

Hi

Looking into your dmesg i see that the firmware loaded by the iwlwifi driver is version 25.15.12.0 .

From this page : https://wireless.wiki.kernel.org/en/users/drivers/iwlwifi#firmware
you can download the latest version, for the 3.19 kernel the 25.17.12.0.tgz is the good one.

Extract it and copy it to /lib/firmware (as root) and reboot.

This solve the issue for me. No more disconnection and perfectly stable.
I hope this will help you !

[Seth Forshee (sforshee)]

@Tasev: Note that firmware version 25.17.12.0 is already available in the latest linux-firmware (version 1.143.1), so there's no need to install it manually.

[Launchpad Janitor (janitor)]

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