Return-path: Received: from mail-qy0-f181.google.com ([209.85.216.181]:36954 "EHLO mail-qy0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753949Ab0LGBUC convert rfc822-to-8bit (ORCPT ); Mon, 6 Dec 2010 20:20:02 -0500 Received: by qyk12 with SMTP id 12so15169047qyk.19 for ; Mon, 06 Dec 2010 17:20:02 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <201012061714.15863.br1@einfach.org> From: Jonathan Guerin Date: Tue, 7 Dec 2010 11:19:45 +1000 Message-ID: Subject: Re: ath5k: Weird Retransmission Behaviour To: =?ISO-8859-1?Q?Bj=F6rn_Smedman?= Cc: Bruno Randolf , linux-wireless , ath5k-devel , nbd@openwrt.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: 2010/12/7 Bj?rn Smedman : > On Mon, Dec 6, 2010 at 9:14 AM, Bruno Randolf wrote: > [snip] >> >> Other examples: >> >> *** txdesc tries 2 >> *** mrr 0 tries 9 rate 12 >> *** mrr 1 tries 2 rate 13 >> *** mrr 2 tries 3 rate 11 >> >> = 16 transmissions in sum. >> >> *** txdesc tries 9 >> *** mrr 0 tries 3 rate 11 >> *** mrr 1 tries 9 rate 8 >> *** mrr 2 tries 3 rate 11 >> >> = 24 transmissions in sum. Again, rate[1] and rate[3] are the same, so why >> bother setting it up twice? > > I remember from experimenting with rate control in madwifi that weird > stuff can happens when you go above ATH_TXMAXTRY = 13 tx attempts in > total (all mrr segments combined). We thought we saw some significant > improvement on poor links when we reduced retries to fit the whole mrr > chain into 13 retries in total, but we didn't have the equipment to > really verify that. Perhaps something you could try Jonathan in your > excellent testbed? I'd be happy to test this if you give me the exact scenario you would like me to run. Incidentally, I didn't set up this testbed, my colleague Konstanty did. You can read about it here: http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5562247 and a copy of the PDF is accessible from my Dropbox: http://dl.dropbox.com/u/2451223/3836_publication_Design_of__2932.pdf. Cheers, Jonathan > > /Bj?rn >