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From: Sujith <m.sujith@gmail.com>
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Message-ID: <19906.621.413439.414030@gargle.gargle.HOWL> (sfid-20110505_034846_227085_8A755104)
Date: Thu, 5 May 2011 07:20:37 +0530
To: Daniel Halperin <dhalperi@cs.washington.edu>
Cc: linux-wireless@vger.kernel.org
Subject: bug: 2 second wireless stall on ath9k link
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	<19906.158.278401.536454@gargle.gargle.HOWL>
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Sujith wrote:
> Daniel Halperin wrote:
> > Hi,
> > 
> > I have two identical Dell Inspiron 530n desktops running latest w-t
> > (07e789c5094735747b3df8a7840f61467575ba9e, master 2011-05-04) on
> > Ubuntu 10.04.2 LTS. I have uninstalled network-manager from both
> > devices and, as far as I can tell, no software processes or daemons
> > interfere with my wireless configurations.
> > 
> > The AP machine has an AR9280-based device and an IWL5300 based device.
> > I blacklist ath9k and iwlagn modules from loading on boot. It is
> > running latest hostap.git, though I've seen the same issue with older
> > versions.
> > 
> > The client machine has one AR9380-based NIC, one IWL5300-based NIC,
> > and one RT2800pci NIC. I blacklist ath9k, iwlagn, and rt2800pci from
> > loading on boot.
> > 
> > When I set up the client to connect (using iwconfig essid) to the AP
> > (no encryption, channel 48 with HT40-) and run iperf, I sometimes see
> > 2-second drops of the connection. I run iperf to generate elastic TCP
> > flows that see ~150 Mbps, and in parallel I run ping <AP> -i 0.2.
> > Here's the ping log:
> 
> Your timing couldn't be better. :)
> https://patchwork.kernel.org/patch/753862/

Hm, is ath9k in AP mode ?
That fix is meant primarily for station mode.

Disabling ANI would be useful to narrow down the issue.
(Since long calibration is every 30 seconds).

Sujith