Return-path: Received: from one.firstfloor.org ([213.235.205.2]:41752 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750764AbZAEPKU (ORCPT ); Mon, 5 Jan 2009 10:10:20 -0500 Date: Mon, 5 Jan 2009 16:24:10 +0100 From: Andi Kleen To: Felix Fietkau Cc: Andi Kleen , Larry Finger , Michael Buesch , linux-wireless@vger.kernel.org, John Linville Subject: Re: rate instability in wireless stack Message-ID: <20090105152410.GT496@one.firstfloor.org> (sfid-20090105_161025_023486_49A3DD07) References: <20090104174123.GW496@one.firstfloor.org> <49615465.4090604@lwfinger.net> <20090105025302.GF496@one.firstfloor.org> <49618497.50809@lwfinger.net> <20090105050248.GG496@one.firstfloor.org> <496193A6.3040608@lwfinger.net> <20090105054830.GJ496@one.firstfloor.org> <49620BE5.9030507@openwrt.org> <20090105142343.GS496@one.firstfloor.org> <49621C36.70602@openwrt.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <49621C36.70602@openwrt.org> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, Jan 05, 2009 at 03:41:58PM +0100, Felix Fietkau wrote: > Andi Kleen wrote: > > With Larry's patch reverted. Rate is still at 1Mbit/s of course. > > This is all only with rtl8180, I didn't try everything on the realtek > > card too. > > > > -Andi > > > > rate throughput ewma prob this prob this succ/attempt success attempts > > TtP 1 0.9 99.2 100.0 1( 1) 23 32 > > 2 0.0 0.0 0.0 0( 0) 0 0 > > 5.5 0.0 0.0 0.0 0( 0) 0 1 > > 11 0.0 0.0 0.0 0( 0) 0 0 > > 6 0.0 0.0 0.0 0( 0) 0 0 > > 9 0.0 0.0 0.0 0( 0) 0 0 > > 12 0.0 0.0 0.0 0( 0) 0 0 > > 18 0.0 0.0 0.0 0( 0) 0 0 > > 24 0.0 0.0 0.0 0( 0) 0 0 > > 36 0.0 0.0 0.0 0( 0) 0 0 > > 48 0.0 0.0 0.0 0( 0) 0 0 > > 54 0.0 0.0 0.0 0( 0) 0 0 > > > > Total packet count:: ideal 25 lookaround 1 > OK, that confirms that Larry's patch was wrong - at least the dump > looks consistent now. > Probably the RT2561 and the RTL8180 simply have a lower Tx power and > thus can't get the signal through the walls as easily as the zd1211rw. That surprises me because I use a real antenna on them which the zd1211rw is just itself. Also some laptops with Intel wireless have no trouble talking through the walls at full rate when I put them on the same position. Hmm perhaps I should try to find a Windows box and see if it works there. That would rule out hardware issues. > If you still think that it's a rate control problem, please try all I don't know what it is, i just know that it doesn't work and from the evidence I gathered so far it looks like a Linux software problem. > the rates individually and see if one of them works better. Forcing the rates works somewhat, but the link quality is very poor (10-15/100) and fluctuates. -Andi -- ak@linux.intel.com