Return-path: Received: from mail-bw0-f46.google.com ([209.85.214.46]:57901 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752036Ab1FFVf2 (ORCPT ); Mon, 6 Jun 2011 17:35:28 -0400 Received: by bwz15 with SMTP id 15so3668880bwz.19 for ; Mon, 06 Jun 2011 14:35:27 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20110606182147.GE2604@tuxdriver.com> References: <20110526151422.GA2382@redhat.com> <1306421442.14995.325.camel@wwguy-huron> <20110606085851.GA2391@redhat.com> <20110606182147.GE2604@tuxdriver.com> From: Daniel Halperin Date: Mon, 6 Jun 2011 14:35:06 -0700 Message-ID: (sfid-20110606_233531_480707_A8CCA130) Subject: Re: [PATCH v2] iwlagn: use cts-to-self protection on 5000 adapters series To: "John W. Linville" Cc: Stanislaw Gruszka , Johannes Berg , Intel Linux Wireless , "linux-wireless@vger.kernel.org" , "Guy, Wey-Yi" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, Jun 6, 2011 at 11:21 AM, John W. Linville wrote: > On Mon, Jun 06, 2011 at 10:58:52AM +0200, Stanislaw Gruszka wrote: >> On Thu, May 26, 2011 at 07:50:42AM -0700, Guy, Wey-Yi wrote: >> > On Thu, 2011-05-26 at 08:14 -0700, Stanislaw Gruszka wrote: >> > > This patch fixes 802.11n stability and performance regression we have >> > > since 2.6.35. It boost performance on my 5GHz N-only network from about >> > > 5MB/s to 8MB/s. Similar percentage boost can be observed on 2.4 GHz. >> > > >> > > These are test results of 5x downloading of approximately 700MB iso >> > > image: >> > > >> > > vanilla: 5.27 5.22 4.94 4.47 5.31 ; avr 5.0420 std 0.35110 >> > > patched: 8.07 7.95 8.06 7.99 7.96 ; avr 8.0060 std 0.055946 >> > > >> > > This was achieved with NetworkManager configured to do not perform >> > > periodical scans, by configuring constant BSSID. With periodical scans, >> > > after some time, performance downgrade to unpatched driver level, like >> > > in example below: >> > > >> > > patched: 7.40 7.61 4.28 4.37 4.80 avr 5.6920 std 1.6683 >> > > >> > > However patch still make better here, since similar test on unpatched >> > > driver make link disconnects with below messages after some time: >> > > >> > > wlan1: authenticate with 00:23:69:35:d1:3f (try 1) >> > > wlan1: authenticate with 00:23:69:35:d1:3f (try 2) >> > > wlan1: authenticate with 00:23:69:35:d1:3f (try 3) >> > > wlan1: authentication with 00:23:69:35:d1:3f timed out >> > > >> > > On 2.6.35 kernel patch helps against connection hangs with messages: >> > > >> > > iwlagn 0000:20:00.0: queue 10 stuck 3 time. Fw reload. >> > > iwlagn 0000:20:00.0: On demand firmware reload >> > > iwlagn 0000:20:00.0: Stopping AGG while state not ON or starting >> > > >> > > Cc: stable@kernel.org # 2.6.35+ >> > > Signed-off-by: Stanislaw Gruszka >> > Acked-by: Wey-Yi Guy >> >> John, can you apply that patch and push upstream? Or should I >> repost? I want backport it to Fedora 2.6.35 as it fixes random >> 11n connection hangs there (common F-14 bug). > > Sorry, I was waiting to see if Daniel was going to reply further... > Gotcha -- I doubt it harms much, and Stanislaw is right that changing RTS/CTS to CTS-self is more efficient. This patch is likely a good thing to have, though I still think there's something else going on ;) Dan