wireless access point won't connect- changed bandwidth in a way we can't support - disconnect

Bug #1192259 reported by Rick Spencer on 2013-06-18
This bug affects 8 people
Affects Status Importance Assigned to Milestone
linux (Ubuntu)

Bug Description

I am staying in an apartment with a shared access point. Ubuntu is unable to connect to that access point, but connects fine to others.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: linux-image-3.9.0-6-generic 3.9.0-6.13 [modified: boot/vmlinuz-3.9.0-6-generic]
ProcVersionSignature: Ubuntu 3.9.0-6.13-generic 3.9.6
Uname: Linux 3.9.0-6-generic x86_64
ApportVersion: 2.10.2-0ubuntu1
Architecture: amd64
 /dev/snd/controlC0: rick 1834 F.... pulseaudio
Date: Tue Jun 18 10:15:46 2013
HibernationDevice: RESUME=UUID=bb5660ec-d14f-4b7b-a8ac-994e0e09af25
InstallationDate: Installed on 2013-06-18 (0 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130617)
MachineType: LENOVO Lenovo IdeaPad U310 Touch
MarkForUpload: True
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.9.0-6-generic.efi.signed root=UUID=f26c50a8-eb98-479c-ad80-1906e5d1e626 ro quiet splash vt.handoff=7
 linux-restricted-modules-3.9.0-6-generic N/A
 linux-backports-modules-3.9.0-6-generic N/A
 linux-firmware 1.109
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 01/29/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: 65CN97WW
dmi.board.asset.tag: No Asset Tag
dmi.board.name: Lenovo
dmi.board.vendor: LENOVO
dmi.board.version: 31900003WIN8 STD MLT
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Lenovo IdeaPad U310 Touch
dmi.modalias: dmi:bvnLENOVO:bvr65CN97WW:bd01/29/2013:svnLENOVO:pnLenovoIdeaPadU310Touch:pvrLenovoIdeaPadU310Touch:rvnLENOVO:rnLenovo:rvr31900003WIN8STDMLT:cvnLENOVO:ct10:cvrLenovoIdeaPadU310Touch:
dmi.product.name: Lenovo IdeaPad U310 Touch
dmi.product.version: Lenovo IdeaPad U310 Touch
dmi.sys.vendor: LENOVO

Jun 18 08:29:40 rick-Lenovo-IdeaPad-U310-Touch kernel: [ 6598.038710] wlan0: AP 00:24:b2:db:d7:30 changed bandwidth in a way we can't support - disconnect

^ This seems to me like the key hint at the issue, it seems like this is probably some new or changed code path being exercised with the latest Saucy kernel for WEP in this particular case.

This change was made by a bot.

Changed in linux (Ubuntu):
status: New → Confirmed
Changed in linux (Ubuntu):
importance: Undecided → High
tags: added: kernel-key
Joseph Salisbury (jsalisbury) wrote :

Probably due to this commit:
30eb1dc - mac80211: properly track HT/VHT operation changes

Joseph Salisbury (jsalisbury) wrote :

There have been lots of changes to mac80211 since commit 30eb1dc. In addition, Saucy will soon be rebased to the latest v3.10 kernel. Can you test v3.10-rc6 to see if it still exhibits the bug? It can be downloaded from:


Seth Forshee (sforshee) wrote :

That's probably the commit which introduces the problem. Basically what seems to be happening is that mac80211 thinks the AP is changing some parameters of the wireless connection that it shouldn't be changing. If testing the 3.10-rc kernel shows that this is still a problem we'll have to try and determine exactly what mac80211 thinks is invalid.

Rick: are you able to find out the model of the router which is giving you trouble?

Joseph Salisbury (jsalisbury) wrote :

Hi Rick,

Just wondering if you had a chance to test the v3.10 kernel, and if it still exhibits this bug?

Changed in linux (Ubuntu Saucy):
status: Confirmed → Incomplete
Joseph Salisbury (jsalisbury) wrote :

Saucy has not been rebased to the 3.10 kernel. Can you test the latest updates and post back if this bug still exists?

a me too on 3.9-1, the router is a WR1043ND in Kyrgyzstan if the regulatory domain matters...

might be some interference with the router state, because it used to work a day before. it's a hostel with many connections.

tags: removed: kernel-key
tags: added: kernel-da-key
Shang Wu (shangwu) wrote :

same issue for me on the 3.11.0-13-generic

Shang Wu (shangwu) wrote :

I was keep getting the "changed bandwidth in a way we can't support - disconnect" when I tried to connect my home wireless router.

I have resolved my issue by go into my home router TotoLink N302R Plus and change the wireless bandwidth to 20MHz instead of 20/40 MHz. Connection seems very stable now. Does this mean iwlwifi has issue handling the 40MHz bandwidth?

Po-Hsu Lin (cypressyew) wrote :

Similiar bug reported: bug 1294558

This bug was nominated against a series that is no longer supported, ie saucy. The bug task representing the saucy nomination is being closed as Won't Fix.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

Changed in linux (Ubuntu Saucy):
status: Incomplete → Won't Fix
To post a comment you must log in.
This report contains Public information  Edit
Everyone can see this information.

Other bug subscribers

Remote bug watches

Bug watches keep track of this bug in other bug trackers.