Bug 735520 - [iwl4965] wireless broken on 11n (F15)
Summary: [iwl4965] wireless broken on 11n (F15)
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 16
Hardware: x86_64
OS: Linux
Target Milestone: ---
Assignee: Stanislaw Gruszka
QA Contact: Fedora Extras Quality Assurance
Depends On:
TreeView+ depends on / blocked
Reported: 2011-09-02 21:44 UTC by Johannes H. Jensen
Modified: 2013-01-02 21:20 UTC (History)
8 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2012-11-13 15:44:26 UTC

Attachments (Terms of Use)
dmesg output with 11n enabled (1.40 KB, text/plain)
2011-09-02 21:44 UTC, Johannes H. Jensen
no flags Details

Description Johannes H. Jensen 2011-09-02 21:44:12 UTC
Created attachment 521291 [details]
dmesg output with 11n enabled

Wireless performance is severely degraded on my ThinkPad X61 with an Intel 4965AGN when using the iwl4965 driver in 11n mode. Not only is all network traffic very slow, but grinds to a complete halt. AFAIK this is a regression from before the iwlagn driver was split.


The symptoms are identical to bug #733269, but the hardware is different and the proposed fix does not help. The only workaround is to disable 11n with the 11n_disable=1 option.

Attached is the dmesg output when 11n is enabled and performance is severely degraded. The output is identical with 11n_disable=1 except for the two lines:

[  802.507084] iwl4965 0000:03:00.0: Aggregation not enabled for tid 0 because
load = 6
[  815.870043] iwl4965 0000:03:00.0: iwl4965_tx_agg_start on ra =
00:25:9c:ca:7b:bc tid = 0

which appear only when 11n is enabled.

Comment 1 Josh Boyer 2012-06-06 19:14:17 UTC
Are you still seeing this with 2.6.43/3.3?

Comment 2 Johannes H. Jensen 2012-06-06 19:45:20 UTC
Yes, I'm still seeing this on F16 running 3.3.5-2.fc16.x86_64.

Please let me know if there's any more information I can help with.

Comment 3 Dave Jones 2012-10-23 15:29:45 UTC
# Mass update to all open bugs.

Kernel 3.6.2-1.fc16 has just been pushed to updates.
This update is a significant rebase from the previous version.

Please retest with this kernel, and let us know if your problem has been fixed.

In the event that you have upgraded to a newer release and the bug you reported
is still present, please change the version field to the newest release you have
encountered the issue with.  Before doing so, please ensure you are testing the
latest kernel update in that release and attach any new and relevant information
you may have gathered.

If you are not the original bug reporter and you still experience this bug,
please file a new report, as it is possible that you may be seeing a
different problem. 
(Please don't clone this bug, a fresh bug referencing this bug in the comment is sufficient).

Comment 4 Justin M. Forbes 2012-11-13 15:44:26 UTC
With no response, we are closing this bug under the assumption that it is no longer an issue. If you still experience this bug, please feel free to reopen the bug report.

Comment 5 Johannes H. Jensen 2013-01-02 21:20:58 UTC
Hi and sorry for the late response. I just tested on F17 with 3.6.10-2.fc17 and the problem has indeed gone away.

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