[Lenovo Thinkpad X1 Carbon 2nd Gen 20A7,20A8] iwlwifi intel 7260 network does not connect

[avlas]

Connection to the home and university wireless fail to connect. In the terminal I see repeated messages "no association and the time is already over". In contrast I can work and send this bug report through the hot spot wireless of my cellphone with no problem. I checked many bugs on the internet and tried many different things, none of those succeeded. For instance, I tried kernel from the proposed repository, I tried with multiple options of the iwlwifi module, I tried installing new versions of the firmware.

03:00.0 Network controller [0280]: Intel Corporation Wireless 7260 [8086:08b2] (rev 83)
 Subsystem: Intel Corporation Dual Band Wireless-AC 7260 [8086:c270]

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: linux-image-3.16.0-28-generic 3.16.0-28.37
ProcVersionSignature: Ubuntu 3.16.0-28.37-generic 3.16.7-ckt1
Uname: Linux 3.16.0-28-generic x86_64
ApportVersion: 2.14.7-0ubuntu8
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: jsardid 2608 F.... pulseaudio
 /dev/snd/controlC0: jsardid 2608 F.... pulseaudio
CurrentDesktop: KDE
Date: Tue Dec 16 11:49:01 2014
EcryptfsInUse: Yes
InstallationDate: Installed on 2014-12-12 (4 days ago)
InstallationMedia: Kubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
MachineType: LENOVO 20A8S30G00
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.16.0-28-generic.efi.signed root=UUID=15cbe5cb-55eb-4579-8e23-dd0b1aa46557 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.16.0-28-generic N/A
 linux-backports-modules-3.16.0-28-generic N/A
 linux-firmware 1.138
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/20/2014
dmi.bios.vendor: LENOVO
dmi.bios.version: GRET42WW (1.19 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20A8S30G00
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: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrGRET42WW(1.19):bd11/20/2014:svnLENOVO:pn20A8S30G00:pvrThinkPadX1Carbon2nd:rvnLENOVO:rn20A8S30G00:rvrSDK0E50510WIN:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 20A8S30G00
dmi.product.version: ThinkPad X1 Carbon 2nd
dmi.sys.vendor: LENOVO

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Did this issue occur in a previous version of Ubuntu, or is this a new issue?

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.18 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/v3.18-vivid/

[avlas (avlas)]

Did this issue occur in a previous version of Ubuntu, or is this a new issue?

Sorry, I cannot say as this is a new laptop and I directly installed this version of Ubuntu.

I'll try the new kernel and let you know...

[avlas (avlas)]

The upstream kernel didn't fix the issue...

[avlas (avlas)]

I found a workaround that I introduce here for the case it can help some other people in my situation, as well as for the case it gives a clue for a potential fix:

- I duplicated my local wifi connection and in one of the two I modified the default options to adhoc, B/G 2.4GHz, Channel 1 (I also changed the label to know which one is each)
- Then I manually connect the modified wifi connection, but right at the time it is requesting an IP, I rapidly connect the other (default) connection

If I do it in this specific order, then the default network works. If I just try to connect either of the two without replicating this sequence, the two fail miserably.

Hope it helps

[penalvch (penalvch)]

avlas, could you please provide your home router manufacturer, model, and firmware version?

As well, while the scope of this report will center around your home router, regarding your university router, do either or both of the following provide a WORKAROUND:
1) Adjust the line in /etc/modprobe.d/iwlwifi.conf to:
options iwlwifi 11n_disable=1

and then restart.

2) (This also applies to your home router): If power management is off, execute at a terminal:
sudo iwconfig wlan0 power off

[avlas (avlas)]

Sorry, I have been busy for some time and in the meantime I used my workaround, which worked quite fine. Also, something has changed since then, as now I don't even have to use that workaround to get the wifi work as expected.

I would like to give you a hint of what was causing the issue and how it got fixed (at least for the moment), but I don't know.

If I see these issues coming back, I'll add more info...

[avlas (avlas)]

Ok, I have more info:

First some context, after a gpu hang I ran into problems with the intel graphics driver with black screen after opening a session, or so I thought, and temporally used in grub options nomodeset or i915.modeset=0.

This caused some issues with the screen resolution, but while I kept that config, my wifi worked perfectly, so I guess there is some weird sort of conflict here.

Then I realized that my black screen was because the video was redirect to some other output, vga, or whatever, even if there was no device connected. I could get my screen back by using the output video button in my laptop.

Once I came back to my original grub configuration, the wifi problems came back, which I still can workaround following the instructions that appear above...

[avlas (avlas)]

I think I found the solution to my problem here http://askubuntu.com/questions/511255/intel-dual-band-wireless-ac-7260-keeps-dropping-wifi

Basically I needed to set the country for iw:

sudo iw reg set US

By this I passed from:

~$ iw reg get
country 00: DFS-UNSET
        (2402 - 2472 @ 40), (3, 20)
        (2457 - 2482 @ 40), (3, 20), NO-IR
        (2474 - 2494 @ 20), (3, 20), NO-OFDM, NO-IR
        (5170 - 5250 @ 40), (3, 20), NO-IR
        (5735 - 5835 @ 40), (3, 20), NO-IR

to:

iw reg get
country US: DFS-UNSET
        (2402 - 2472 @ 40), (3, 27)
        (5170 - 5250 @ 40), (3, 17)
        (5250 - 5330 @ 40), (3, 20), DFS
        (5490 - 5600 @ 40), (3, 20), DFS
        (5650 - 5710 @ 40), (3, 20), DFS
        (5735 - 5835 @ 40), (3, 30)
        (57240 - 63720 @ 2160), (N/A, 40)

Now my wifi is working fine.

[Launchpad Janitor (janitor)]

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