Subject: Re: [PATCH 2/3] mac80211: Add a timeout for frames in the RX
 reorder buffer
From: Marcel Holtmann <marcel@holtmann.org>
To: Jouni Malinen <j@w1.fi>
Cc: Jouni Malinen <jouni.malinen@atheros.com>,
	"John W. Linville" <linville@tuxdriver.com>,
	Johannes Berg <johannes@sipsolutions.net>,
	linux-wireless@vger.kernel.org
In-Reply-To: <20090509080838.GA1206@jm.kir.nu>
References: <20090505173512.349795688@atheros.com>
	 <20090505173550.273830766@atheros.com>
	 <1241709323.4903.25.camel@localhost.localdomain>
	 <1241833703.4903.83.camel@localhost.localdomain>
	 <20090509080838.GA1206@jm.kir.nu>
Content-Type: text/plain
Date: Sat, 09 May 2009 17:08:58 -0700
Message-Id: <1241914138.2783.4.camel@localhost.localdomain>
Mime-Version: 1.0
Sender: linux-wireless-owner@vger.kernel.org

Hi Jouni,

> > so I finally got the debug output for you. Took only over a day :)
> 
> Thanks! Would you happen to have timing information available for these
> (e.g., from klogd)? It looks like the AP is sending out an ADDBA Request
> to update some parameters, but we currently ignore that request.
> However, at least in this particular case, our RX reorder bug head_seq
> matches with the ssn from the ADDBA Request, so I'm not sure whether
> ignoring the ADDBA contents is really causing harm here (anyway, we
> should really process these updates, too).
> 
> The timeouts on RX reorder frames look similar to what I have seen in my
> tests and the workaround was indeed trying to address that type of
> issue, so it is nice to hear that it helped in this case, too.

so I enabled timing information for dmesg and got another report. It is
not exactly the same and I don't know how and why it happened.

[  249.579036] phy0: AddBA: ssn=50, dialog_token=1 tid=0 timeout=0ba_policy=1
[  249.579046] addba: d0 00 40 01 00 16 eb 05 46 5c 00 1c f0 62 88 5b 
[  249.579052] addba: 00 1c f0 62 88 5b 30 8f 03 00 01 02 10 00 00 20 
[  249.579057] addba: 03 
[  249.579073] Rx A-MPDU request on tid 0 result 0
[  250.572022] phy0: AddBA: ssn=178, dialog_token=2 tid=0 timeout=0ba_policy=1
[  250.572032] addba: d0 00 40 01 00 16 eb 05 46 5c 00 1c f0 62 88 5b 
[  250.572038] addba: 00 1c f0 62 88 5b e0 8f 03 00 02 02 10 00 00 20 
[  250.572042] addba: 0b 
[  250.572048] phy0: RX reorder buf: head_seq=178 ssn=50 buf_size=64 stored_mpdu_num=0 timeout=0 index=0; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
[  250.572108] unexpected AddBA Req from 00:1c:f0:xx:xx:xx on tid 0
[  266.263651] Open BA session requested for 00:1c:f0:xx:xx:xx tid 0
[  266.263659] iwlagn 0000:03:00.0: iwl_tx_agg_start on ra = 00:1c:f0:xx:xx:xx tid = 0
[  266.263726] activated addBA response timer on tid 0
[  266.265534] wrong addBA response token, tid 0
[  267.263467] addBA response timer expired on tid 0
[  267.263516] Stopping Tx BA session for 00:1c:f0:xx:xx:xx tid 0
[  326.083081] Open BA session requested for 00:1c:f0:xx:xx:xx tid 0
[  326.083097] iwlagn 0000:03:00.0: iwl_tx_agg_start on ra = 00:1c:f0:xx:xx:xx tid = 0
[  326.083197] activated addBA response timer on tid 0
[  326.088517] wrong addBA response token, tid 0
[  327.080206] addBA response timer expired on tid 0
[  327.080262] Stopping Tx BA session for 00:1c:f0:xx:xx:xx tid 0

This kernel is running latest wireless-testing.git with debug patch and
the disassoc change (for testing) from Johannes.

Regards

Marcel