Poor Wi-Fi connectivity when connecting USB dock

[Jonas G. Drange]

Reproduce:
Insert USB dock (Kensington with usb sound card, ethernet card) cable into any USB port

What happens:
Wi-Fi connectivity worsens and eventually disconnects.
Pinging an online target gives me
[1432638474.615293] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=11 ttl=54 time=1172 ms
[1432638474.636669] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=12 ttl=54 time=185 ms
[1432638475.496000] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=13 ttl=54 time=44.3 ms
[1432638477.638814] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=14 ttl=54 time=1185 ms
[1432638477.644744] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=15 ttl=54 time=192 ms
[1432638478.498248] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=16 ttl=54 time=44.4 ms
[1432638479.662460] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=17 ttl=54 time=207 ms
[1432638480.547434] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=18 ttl=54 time=90.9 ms
[1432638482.597835] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=19 ttl=54 time=1140 ms
[1432638482.601590] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=20 ttl=54 time=144 ms
[1432638484.648946] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=21 ttl=54 time=1191 ms
[1432638484.649794] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=22 ttl=54 time=193 ms
[1432638485.502967] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=23 ttl=54 time=45.1 ms
[1432638487.301295] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=24 ttl=54 time=842 ms
[1432638488.649794] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=25 ttl=54 time=1191 ms
[1432638488.662959] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=26 ttl=54 time=196 ms
[1432638489.514683] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=27 ttl=54 time=46.7 ms
[1432638491.653511] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=28 ttl=54 time=1183 ms
[1432638491.655011] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=29 ttl=54 time=176 ms
[1432638493.659119] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=30 ttl=54 time=1179 ms
[1432638493.664250] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=31 ttl=54 time=177 ms
[1432638494.534200] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=32 ttl=54 time=45.9 ms
…

Disconnecting the USB cable restores the connectivity:
[1432638514.584374] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=52 ttl=54 time=48.5 ms
[1432638515.577822] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=53 ttl=54 time=40.1 ms
[1432638516.579000] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=54 ttl=54 time=39.9 ms
[1432638517.580760] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=55 ttl=54 time=40.5 ms
[1432638518.583465] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=56 ttl=54 time=41.4 ms
[1432638519.583923] 64 bytes from fra07s30-in-f5.1e100.net (173.194.112.101): icmp_seq=57 ttl=54 time=40.1 ms
…

What should have happened:
Connectivity should not be affected by a connected USB dock

Steps taken to debug:
* I've told NetworkManager not to manage the USB network card so that it appears unmanaged. This makes no difference.
* I've tried older kernels, e.g. 3.14 with no luck
* It does not matter what is connected to the dock

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: linux-image-3.19.0-18-generic 3.19.0-18.18
ProcVersionSignature: Ubuntu 3.19.0-18.18-generic 3.19.6
Uname: Linux 3.19.0-18-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: jonas 1514 F.... pulseaudio
CurrentDesktop: Unity
Date: Tue May 26 13:08:44 2015
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-precise-amd64-20120703-2
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=7b9cb658-95dd-4e13-a587-d6d0d59ae7e4
InstallationDate: Installed on 2013-08-27 (637 days ago)
InstallationMedia: Ubuntu 12.04 "Precise" - Build amd64 LIVE Binary 20120703-15:08
MachineType: Dell Inc. Dell System XPS L322X
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.19.0-18-generic root=UUID=221de9c1-f10a-4be4-9273-5c12864c8680 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.19.0-18-generic N/A
 linux-backports-modules-3.19.0-18-generic N/A
 linux-firmware 1.143.1
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 05/15/2013
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A09
dmi.board.name: 0PJHXN
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: 0.1
dmi.modalias: dmi:bvnDellInc.:bvrA09:bd05/15/2013:svnDellInc.:pnDellSystemXPSL322X:pvr:rvnDellInc.:rn0PJHXN:rvrA00:cvnDellInc.:ct8:cvr0.1:
dmi.product.name: Dell System XPS L322X
dmi.sys.vendor: Dell Inc.

[Brad Figg (brad-figg)]

This change was made by a bot.

[Jonas G. Drange (jonas-drange)]

@penalvch, thanks. Flashing A10 seems to have solved it.

sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date
A10
08/28/2013

[Jonas G. Drange (jonas-drange)]

I was wrong. Wi-Fi slowly dies after plugging in the USB dock.

[Brad Figg (brad-figg)]

This change was made by a bot.

[penalvch (penalvch)]

Jonas G. Drange, 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/Kernel/MainlineBuilds ? 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 by clicking on the yellow circle with a black pencil icon, next to the word Tags, located at the bottom of the report description:
kernel-fixed-upstream
kernel-fixed-upstream-X.Y-rcZ

Where XY and Z are numbers corresponding to the kernel version.

If the mainline kernel does not fix this bug, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-X.Y-rcZ

Please note, an error to install the kernel does not fit the criteria of kernel-bug-exists-upstream.

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.

[Jonas G. Drange (jonas-drange)]

On 3 June 2015 at 02:05, Christopher M. Penalver <
<email address hidden>> wrote:

> Jonas G. Drange, could you please test the latest upstream kernel
>

​Sure. But there are a couple of things that are making me suspect the
ath9k driver:
1. Reloading the driver (rmmod ath9k && modprobe ath9k) makes this less of
a problem
2. Turning (soft) off bluetooth seems to improve the situation as well. And
I see a lot of bluetooth+ath9k related issues.

So before I do a bisect, do we know that the ath9k driver gets updated
after 3.19.0-18-generic?​

[penalvch (penalvch)]

Jonas G. Drange, the latest mainline kernel is 4.1-rc6.

[penalvch (penalvch)]

Jonas G. Drange, the issue you are reporting is an upstream one. Could you please report this problem to the appropriate mailing list (ath9k-devel and linux-wireless) by following the instructions verbatim at https://wiki.ubuntu.com/Bugs/Upstream/kernel ?

Please provide a direct URL to your e-mail to the mailing list once you have made it so that it may be tracked via http://vger.kernel.org/vger-lists.html . It can take a day for the new e-mail to show up in the respective archive.

Thank you for your understanding.