[Lenovo ThinkPad T540p] Intel Wireless Dual Band 7260AC fails to connect

[Federico Sassi]

I have a Lenovo Thinkpad T540p and the wireless connection isn't working correctly. It will list the available networks but when trying to connect it will keep asking for the password or when it connects the connection will last only few seconds and the packet loss on a ping will be very high.

I've followed bug https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1354975 in order to find a solution but without luck. I've tried to turn off power management, install latest kernel ( linux-image-3.17.0-031700-generic ) and related updated firmware according to http://wireless.kernel.org/en/users/Drivers/iwlwifi . Tried also the updated firmware for the older kernel and with the older kernel.
I've tried also Ubuntu 14.10 with same results. I've tried to move closer to the router but with no change at all.

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

sudo lshw -C network
network
       description: Wireless interface
       product: Wireless 7260
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:04:00.0
       logical name: wlan0
       version: 83
       serial: e8:b1:fc:d2:e3:9e
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlwifi driverversion=3.13.0-40-generic firmware=22.24.8.0 latency=0 link=no multicast=yes wireless=IEEE 802.11abgn
       resources: irq:47 memory:e1400000-e1401fff

WORKAROUND: Disable 802.11n on the router.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-40-generic 3.13.0-40.69
ProcVersionSignature: Ubuntu 3.13.0-40.69-generic 3.13.11.10
Uname: Linux 3.13.0-40-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: fsassi 1930 F.... pulseaudio
 /dev/snd/controlC1: fsassi 1930 F.... pulseaudio
Date: Thu Nov 27 16:13:07 2014
HibernationDevice: RESUME=UUID=650269f1-902f-4143-8cd4-27d1631b5d05
InstallationDate: Installed on 2014-11-26 (0 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
MachineType: LENOVO 20BECTO1WW
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-40-generic.efi.signed root=UUID=00883037-516d-4066-9e6b-581d1c2a4b7d ro quiet splash vt.handoff=7
PulseList:
 Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied
 No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-40-generic N/A
 linux-backports-modules-3.13.0-40-generic N/A
 linux-firmware 1.127.8
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 09/22/2014
dmi.bios.vendor: LENOVO
dmi.bios.version: GMET67WW (2.15 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20BECTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: SDK0E50512 STD
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrGMET67WW(2.15):bd09/22/2014:svnLENOVO:pn20BECTO1WW:pvrThinkPadT540p:rvnLENOVO:rn20BECTO1WW:rvrSDK0E50512STD:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 20BECTO1WW
dmi.product.version: ThinkPad T540p
dmi.sys.vendor: LENOVO

[Brad Figg (brad-figg)]

This change was made by a bot.

[Federico Sassi (fsassi)]

I've captured connection problem using wifi-debug http://people.canonical.com/~sforshee/wifi-debug
shall I post it here?

Moreover I forgot to add that I already had disabled 11n by:
echo "options iwlwifi 11n_disable=8" | sudo tee -a /etc/modprobe.d/iwlwifi.conf

[Federico Sassi (fsassi)]

Dear Christopher,
thank you for answering and pointing out the old bios version.

I've updated the BIOS to the latest version and tried again with both kernels and firmware.
The result didn't change, thus the wireless is still not working correctly.

As you requested this is the output that confirms the correct bios update.
sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date
GMET68WW (2.16 )
11/07/2014

What are the next steps?

Regards,
  Federico

[penalvch (penalvch)]

Federico Sassi, 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-rc6

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.

[Federico Sassi (fsassi)]

Dear Christopher,
I've just tested with the latest one and it is still not working.
I've tested it with all different firmware version possible: .8 .9 and .10

uname -a
Linux henesis15 3.18.0-031800rc7-generic #201411302035 SMP Mon Dec 1 01:36:38 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

Thank you for your support.

[penalvch (penalvch)]

Federico Sassi, could you please provide the missing information following https://wiki.ubuntu.com/Kernel/LinuxWireless ?

[Federico Sassi (fsassi)]

Christopher,
I cannot do that now because it is the office router and other people are using it.
I'll provide that information as soon as possible even if it is a long list of tests.

Regards

[Federico Sassi (fsassi)]

Shall I perform the tests with the lastest upstream kernel or with the ubuntu 14.04 stock one?

[Federico Sassi (fsassi)]

I performed a few preliminary test with both kernels and the wireless seems working with only G networks.
I had to disable the N part on the routers.

[penalvch (penalvch)]

Federico Sassi, if your routers broadcast on both n and g, you could just disable n on your laptop via setting the following in /etc/modprobe.d/iwlwifi.conf :
options iwlwifi 11n_disable=1

Also, the latest mainline kernel to test with is http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.18-vivid/ .

[Federico Sassi (fsassi)]

Dear Christopher,
your solution works but the connection is not 100% reliable.

The laptop can connect, even send/receive large files but I also experience lags and general slowness.
Moreover sometime it doesn't even connect and I have to reboot the laptop or the router.
(test done on 3.13)

[penalvch (penalvch)]

Federico Sassi, glad to hear there is improvement for you. Does this further improve with the latest mainline kernel 3.18.1?

[Federico Sassi (fsassi)]

I'm testing it right now.
I have standard firmware thus the driver doesn't find the latest iwlwifi-7260-10.ucode and fall back to the 9 version.

Shall I install the 10 version from http://wireless.kernel.org/en/users/Drivers/iwlwifi or keep using the 9?

[Federico Sassi (fsassi)]

The wifi works with the 9 (disabling the 11n as before) and kernel 3.18.1-031801-generic

[penalvch (penalvch)]

Federico Sassi, the next step is to fully reverse commit bisect from kernel 3.18-rc7 to 3.18.1 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

[Federico Sassi (fsassi)]

Dear Christopher,
I didn't explain myself correctly. The still wifi works with kernel 3.18.1

[Federico Sassi (fsassi)]

Dear Christopher,
I didn't explain myself correctly. The wifi *still* works with kernel 3.18.1 (always disabling the 11n )

[penalvch (penalvch)]

Federico Sassi, just to clarify, is disabling 11n and using 3.18.1 provided more reliability than the default Ubuntu kernel?

[Federico Sassi (fsassi)]

ok, I understand.
I'll use the wifi for a period of time with kernel 3.18.1 and 3.13.
Since there are going to be holidays (and I'll not be in the office) I'll get back to you in the new year.
Thank you

[Federico Sassi (fsassi)]

Have I to use the same firmware?
with kernel 3.18.1 I'm using firmware version 23.214.9.0

[penalvch (penalvch)]

Federico Sassi, please use the firmware that came with Ubuntu by default. However, if you notice a difference using the default firmware (bad or good) please feel free to advise to this.

[Seth Forshee (sforshee)]

Frederico: New firmware was recently released for you wireless hardware which addresses a number of issues. Please ensure your system is fully up to date, then reboot and see if this fixes your connection issues. Thanks!

[Federico Sassi (fsassi)]

Dear Seth,
I tested both stock kernel and 3.18.1 (with firmare 25.228.9.0) that I've installed.
Now the wireless card CAN connect to a network and stay connected for a few hours (sometimes) with both kernels BUT the transmission speed is very low (few hunderds of KB/sec) and not continuoisly (by looking in the Ubuntu's system monitor it is for a few seconds then pause then tramsit again).
Moreover the stability is pretty bad, the signal is often lost and tramsitting a large file over the wlan is unfeasible.
Moreover even just webbrowsing is frustating since the card seems to "sleep" for a few seconds.

If enabling the 11n the situation is just worse.

If I can do some further specific (quantitative) testing I would be glad to help.

[Federico Sassi (fsassi)]

Dear Christopher,
what have I to add?

[penalvch (penalvch)]

Federico Sassi, all the missing information requested in https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1397032/comments/8 .

[Launchpad Janitor (janitor)]

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