[Dell Precision M4800] iwlwifi regularly loses connection on Intel 7260

[arty]

When connecting to my Speedport W 723V Typ A router, every 10 minutes my WiFi disconnects and a line like this appears in syslog:
Dec 24 11:31:31 work kernel: [ 2721.017478] wlan0: deauthenticated from 10:c6:1f:2c:49:56 (Reason: 7=CLASS3_FRAME_FROM_NONASSOC_STA)
...
Dec 24 11:31:46 work NetworkManager[902]: <info> (wlan0): device state change: activated -> failed (reason 'SSID not found') [100 120 53]

The network disappears from the list and only becomes visible after I disable and re-enable networking via the network applet.

I don't remember seeing this problem at work where they use Cisco routers.

My environment:
+ Encryption WPA2 or none.
+ Channels 1, 3, 4, 6, 8, or 11.
+ 3-4 meters away from the access point.
+ 802.11n
+ 17 other WiFi access points broadcasting.

03:00.0 Network controller [0280]: Intel Corporation Wireless 7260 [8086:08b1] (rev 73)
 Subsystem: Intel Corporation Dual Band Wireless-AC 7260 [8086:4470]

WORKAROUND: /etc/modprobe.d/iwlwifi.conf :
options iwlwifi 11n_disable=1

Drops did not cause loss of my network, and reconnects happened mostly in the same second. However at some moments there were just too many drops.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: linux-image-3.16.0-28-generic 3.16.0-28.38
ProcVersionSignature: Ubuntu 3.16.0-28.38-generic 3.16.7-ckt1
Uname: Linux 3.16.0-28-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.14.7-0ubuntu8
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: treguben 2520 F.... pulseaudio
 /dev/snd/controlC0: treguben 2520 F.... pulseaudio
CurrentDesktop: Unity
Date: Wed Dec 24 15:06:25 2014
HibernationDevice: RESUME=UUID=82445dd2-3bcf-42f7-ae59-4fba694e25de
InstallationDate: Installed on 2014-12-11 (12 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
MachineType: Dell Inc. Precision M4800
ProcFB: 0 EFI VGA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.16.0-28-generic.efi.signed root=UUID=9a116abe-59b9-48b8-abe4-5064a191ac51 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: 12/03/2014
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A11
dmi.board.name: 0T3YTY
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 9
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA11:bd12/03/2014:svnDellInc.:pnPrecisionM4800:pvr01:rvnDellInc.:rn0T3YTY:rvrA00:cvnDellInc.:ct9:cvr:
dmi.product.name: Precision M4800
dmi.product.version: 01
dmi.sys.vendor: Dell Inc.

[Brad Figg (brad-figg)]

This change was made by a bot.

[arty (me-arty)]

Following commands reconnect to the network:
sudo rmmod iwlmvm
sudo rmmod iwlwifi
sudo modprobe iwlwifi

[penalvch (penalvch)]

arty, thank you for reporting this and helping make Ubuntu better. Could you please advise if the firmware of your router is the latest Version (1.01.009) as per http://hilfe.telekom.de/hsp/cms/content/HSP/de/3388/FAQ/theme-293811306/Speedport-W-723V-Typ-A ?

If not, could you please update it to it, and advise if this changes anything?

[arty (me-arty)]

Yes, the firmware is the latest version. I cannot rely on its quality though, i.e. its web-interface now uses an expired HTTPS certificate.

[penalvch (penalvch)]

arty, 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-3.19-rc1

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.

[arty (me-arty)]

Christopher, your link redirects now to https://wiki.ubuntu.com/Kernel/MainlineBuilds and this page has a lot of things, so I'm not really certain which kernels to test. Do you mean the ones from here http://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D ?

[arty (me-arty)]

Bug still exists in http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.19-rc1-vivid/

[penalvch (penalvch)]

arty, does this issue occur if you switch to a mode with 802.11g only (not 802.11g+802.11n)?

[arty (me-arty)]

I have added following line to my /etc/modprobe.d/iwlwifi.conf:
options iwlwifi 11n_disable=1

After reboot and some testing I saw an improvement: drops did not cause "loss" of my network, and reconnects happened mostly in the same second. However at some moments there were just too many drops:

sudo grep "7=" /var/log/syslog
Dec 28 16:01:38 work kernel: [16070.774695] wlan0: deauthenticated from 10:c6:1f:2c:49:56 (Reason: 7=CLASS3_FRAME_FROM_NONASSOC_STA)
Dec 28 16:01:39 work kernel: [16071.847526] wlan0: deauthenticated from 10:c6:1f:2c:49:56 (Reason: 7=CLASS3_FRAME_FROM_NONASSOC_STA)
Dec 28 16:01:47 work kernel: [16079.850216] wlan0: deauthenticated from 10:c6:1f:2c:49:56 (Reason: 7=CLASS3_FRAME_FROM_NONASSOC_STA)
Dec 28 16:01:49 work kernel: [16081.521459] wlan0: deauthenticated from 10:c6:1f:2c:49:56 (Reason: 7=CLASS3_FRAME_FROM_NONASSOC_STA)
Dec 28 16:01:54 work kernel: [16086.639618] wlan0: deauthenticated from 10:c6:1f:2c:49:56 (Reason: 7=CLASS3_FRAME_FROM_NONASSOC_STA)
Dec 28 16:01:56 work kernel: [16088.600946] wlan0: deauthenticated from 10:c6:1f:2c:49:56 (Reason: 7=CLASS3_FRAME_FROM_NONASSOC_STA)
Dec 28 16:01:59 work kernel: [16091.757765] wlan0: deauthenticated from 10:c6:1f:2c:49:56 (Reason: 7=CLASS3_FRAME_FROM_NONASSOC_STA)

[penalvch (penalvch)]

arty, could you please provide the missing information (no need to provide things previously provided again) following https://wiki.ubuntu.com/Kernel/LinuxWireless ?

[arty (me-arty)]

I cannot adjust WiFi network parameters to see whether this would affect the reproducibility of the bug. However here are more details about network's parameters:

4b) WPA2-PSK
4c) No MAC filtering
4d) No QoS AFAIK
4e) I don't think the router exposes the beacon interval value at all
4f) I didn't enable any firewall on the router
4g) The problem has happened on several channels.

5) At least 4 other WiFi devices do not have problems like this one.
6) The distance to AP was about 3-4 meters
7) The only "obstruction" was a wooden shelf with big holes like this one http://www.ikea.com/de/de/catalog/products/30275861/
7a) I could not test this
8) I do not see this problem at work with Cisco APs, however we don't get a big competition for channels at work. There are a lot of different private APs visible in my apartment.
9) I have never tried that with previous releases. I do not have the option to try.
10) Since I have already tried the latest 3.19-rc1 kernel, I don't see the point to test compat-wireless
11) Yes, it occurs in 3.19-rc1
13) I will try the ndiswrapper later.
16) I'm using linux-firmware 1.138. I haven't tried the previous version. Latest Intel firmware is from 3/25/2014, I assume it's already included in linux-firmware 1.138.

[penalvch (penalvch)]

arty, regarding your answers:
4b) WPA2-PSK -> If you remove encryption entirely, or adjust it to WPA-PSK/TKIP, WEP does it change anything?
4d) No QoS AFAIK -> So, in your router, what options do you have?
4f) I didn't enable any firewall on the router -> Does your router have an option to disable this?
4g) The problem has happened on several channels. -> Which ones specifically? Did you try them all?
5) At least 4 other WiFi devices do not have problems like this one. -> What devices/OSes specifically?
9) I have never tried that with previous releases. I do not have the option to try. -> One may test prior releases (live environment is fine) via http://releases.ubuntu.com/ . Saucy would be helpful as it tests the next oldest firmware version for your chipset.
10) Since I have already tried the latest 3.19-rc1 kernel, I don't see the point to test compat-wireless -> compat-wireless has the commits from linux-next in them, which is more advanced than 3.19-rc1 (linux-stable). Could you please advise to this?
13) I will try the ndiswrapper later. -> Please advise to this as it working rules out hardware failure.
16) I'm using linux-firmware 1.138. I haven't tried the previous version. Latest Intel firmware is from 3/25/2014, I assume it's already included in linux-firmware 1.138. -> It's not. I've adjusted the article to better inform on this.

[Seth Forshee (sforshee)]

arty: linux-firmware 1.138.1 has just been released with the latest firmware for your hardware. Please ensure your system is fully up to date, reboot, and see if this helps at all. Thanks!

[arty (me-arty)]

I have tried linux-firmware 1.138.1 and the bug still happens.

Regarding some other questions:

4d) I confirm: no QoS. It's a very basic router, the most advanced feature is port forwarding.
4f) Some kind of firewall is enabled and it's not possible to turn it off.
4g) I have not tried all the channels, I tried 1, 3, 4, 6, 8, 11. Hard to test all, usually most are taken by nearby networks.
5) 3 Android 4.x devices (Galaxy S3, S4, Tab 2) and Panasonic SmartTV Viera TX-42ASW604W
16) According to Seth linux-firmware 1.138.1 has the latest firmware, I use it and still see the bug

Things still to test:

4b) Disable encryption
9) Previous releases
13) NDIS-wrapper

[arty (me-arty)]

4b) With encryption disabled the bug still happens

[arty (me-arty)]

9) I have tried the live CD of Sausy and the bug happens there as well, though is reported slightly differently:

Jan 10 12:56:06 ubuntu kernel: [ 765.792687] wlan0: deauthenticated from 10:c6:1f:2c:49:56 (Reason: 7)
Jan 10 12:56:06 ubuntu wpa_supplicant[2439]: wlan0: CTRL-EVENT-DISCONNECTED bssid=10:c6:1f:2c:49:56 reason=7
Jan 10 12:56:07 ubuntu kernel: [ 765.828307] cfg80211: Calling CRDA to update world regulatory domain
Jan 10 12:56:07 ubuntu NetworkManager[1506]: <info> (wlan0): supplicant interface state: completed -> disconnected

Reconnection happens after several seconds.

Should I try that in earlier releases?

[arty (me-arty)]

10) I could not figure out how to try compat-wireless. Could someone please improve documentation on how to do that? Many other bug reporters might benefit from that as well.

https://wiki.ubuntu.com/Kernel/LinuxWireless#Compat-wireless_from_upstream tells to use instructions from page that does not contain instructions. It also tells to use latest development branch from a page that only lists stable releases.

I would really appreciate steps like "download latest from this list, run following commands, reboot".

[penalvch (penalvch)]

arty, the article intends click-for-click instructions. However, in the case of 10) upstream removed their click-for-click instructions from their wiki. Hence, I'll do a quick wording adjustment on the article for now, and circle back on click-for-click instructions.

Regarding prior release testing, I'm presently satisfied with the Saucy test.

[arty (me-arty)]

13) NDIS wrapper seems not to support the drivers for 7260.

First of all, wiki page https://help.ubuntu.com/community/WifiDocs/Driver/Ndiswrapper says the list of supported drivers is here http://sourceforge.net/apps/mediawiki/ndiswrapper/index.php?title=Main_Page. The actual list probably should be here https://sourceforge.net/p/ndiswrapper/ndiswrapper/Main_Page/ , but all the links on this page look dead to me. So I have tried the drivers for windows 7 32 and 64 bit. 32 didn't install. 64 was installed:

ndiswrapper -l:
netwsw02 : driver installed
 device (8086:08B1) present (alternate driver: iwlwifi)

but didn't work:

Jan 10 14:26:28 work kernel: [ 836.269795] ndiswrapper version 1.59 loaded (smp=yes, preempt=no)
Jan 10 14:26:28 work loadndisdriver: loadndisdriver: load_driver(327): file netwfw02.dat is ignored
Jan 10 14:26:28 work adndisdriver: loadndisdriver: load_driver(364): couldn't load driver netwsw02
Jan 10 14:26:28 work kernel: [ 836.276859] ndiswrapper (import:232): unknown symbol: ntoskrnl.exe:'EtwUnregister'
Jan 10 14:26:28 work loadndisdriver: loadndisdriver: load_driver(364): couldn't load driver netwsw02
Jan 10 14:26:28 work kernel: [ 836.276866] ndiswrapper (import:232): unknown symbol: ntoskrnl.exe:'EtwRegister'
…
Jan 10 14:26:28 work kernel: [ 836.277045] ndiswrapper (import:232): unknown symbol: NDIS.SYS:'NdisAllocateMemoryWithTagPriority'
Jan 10 14:26:28 work kernel: [ 836.277048] ndiswrapper (load_sys_files:200): couldn't prepare driver 'netwsw02'
Jan 10 14:26:28 work kernel: [ 836.277561] ndiswrapper (load_wrap_driver:103): couldn't load driver netwsw02; check system log for messages from 'loadndisdriver'
Jan 10 14:26:28 work kernel: [ 836.279454] usbcore: registered new interface driver ndiswrapper
Jan 10 14:28:48 work kernel: [ 975.569955] usbcore: deregistering interface driver ndiswrapper

[Po-Hsu Lin (cypressyew)]

Status changed to "Confirmed" since arty has already answered all questions in #13

[arty (me-arty)]

Christopher, if I run `make install` after building the kernel, it would only copy compiled modules to the proper folder? Won't it corrupt existing kernels or something? I'm not looking forward to reinstalling the whole system :)

[penalvch (penalvch)]

arty, as per http://www.dell.com/support/home/us/en/19/Drivers/DriversDetails?driverId=V42DW&fileId=3502854647&osCode=BIOSA&productCode=precision-m4800-workstation&languageCode=EN&categoryId=BI an update to your computer's buggy and outdated BIOS is available (A16). If you update to this following https://help.ubuntu.com/community/BIOSUpdate does it change anything?

For more on BIOS updates and linux, please see https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette .

Please note your current BIOS is already in the Bug Description, so posting this on the old BIOS would not be helpful. As well, you don't have to create a new bug report.

Once the BIOS is updated, if the problem is still reproducible:
1) Please provide the output of the following terminal command (not perform an apport-collect):
sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date
2) Please make a comment specifically advising on if there was an improvement or not.
3) Please mark this report Status Confirmed. If it's not reproducible, please mark this as Invalid.

Thank you for your understanding.

[arty (me-arty)]

I can't reproduce the bug because I don't have that router anymore. So I mark this report as invalid.