From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A97CE95A8E for ; Mon, 9 Oct 2023 06:54:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345332AbjJIGyi (ORCPT ); Mon, 9 Oct 2023 02:54:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35148 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345305AbjJIGyf (ORCPT ); Mon, 9 Oct 2023 02:54:35 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B0EFBA4; Sun, 8 Oct 2023 23:54:34 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9EE01C433C8; Mon, 9 Oct 2023 06:54:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1696834474; bh=rZrIcDQhefr0DHgoymWmiWlPeKqu+JDo4LZvNnP0GxI=; h=Subject:From:In-Reply-To:References:To:Cc:Date:From; b=SWGMwF5l5eeF+ti9rjZXEHhfcSF0LGQYWh8xIPYIGoj8pM/LqfHI5Cf56YARyJXiz qqFHxhaWOMPc2Ip/YEUPbdK6p4HpVLderIYYmvqlGDn2fxj6jnAUhDIulH/Q5dXXTw +d7ODVAAmKNZWBG3NbTAg0m2LCVgMxWxWP64OXhyn+D58IMKnGqXWtM0KoeXfpT/Y8 JuutbfY3TxgbVMHwyFlGOh7c2YlCrGJOqCg31PPTxnw+GqNWful9vnrHT9gVwKT6ND 9+Lqp/0vlZtdkQIvlkJo/0MKzv2ubXVSE2zhEWCTF5G4zWGqT/cBghNkYIJQtppym2 Y3JAUPFb4CvHQ== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH v2] wifi: wfx: fix case where rates are out of order From: Kalle Valo In-Reply-To: <20231004123039.157112-1-jerome.pouiller@silabs.com> References: <20231004123039.157112-1-jerome.pouiller@silabs.com> To: =?utf-8?b?SsOpcsO0bWUgUG91aWxsZXI=?= Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, Felix Fietkau , Felipe Negrelli Wolter , Olivier Souloumiac , Alexandr Suslenko , =?utf-8?b?SsOpcsO0bWUgUG91aWxs?= =?utf-8?b?ZXI=?= User-Agent: pwcli/0.1.1-git (https://github.com/kvalo/pwcli/) Python/3.11.2 Message-ID: <169683447045.2071896.3998375753268021178.kvalo@kernel.org> Date: Mon, 9 Oct 2023 06:54:32 +0000 (UTC) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jérôme Pouiller wrote: > From: Felipe Negrelli Wolter > > When frames are sent over the air, the device always applies the data > rates in descending order. The driver assumed Minstrel also provided > rate in descending order. > > However, in some cases, Minstrel can a choose a fallback rate greater > than the primary rate. In this case, the two rates was inverted, the > device try highest rate first and we get many retries. > > Since the device always applies rates in descending order, the > workaround is to drop the rate when it higher than its predecessor in > the rate list. Thus [ 4, 5, 3 ] becomes [ 4, 3 ]. > > This patch has been tested in isolated room with a series of > attenuators. Here are the Minstrel statistics with 80dBm of attenuation: > > Without the fix: > > best ____________rate__________ ____statistics___ _____last____ ______sum-of________ > mode guard # rate [name idx airtime max_tp] [avg(tp) avg(prob)] [retry|suc|att] [#success | #attempts] > HT20 LGI 1 S MCS0 0 1477 5.6 5.2 82.7 3 0 0 3 4 > HT20 LGI 1 MCS1 1 738 10.6 0.0 0.0 0 0 0 0 1 > HT20 LGI 1 D MCS2 2 492 14.9 13.5 81.5 5 0 0 5 9 > HT20 LGI 1 C MCS3 3 369 18.8 17.6 84.3 5 0 0 76 96 > HT20 LGI 1 A P MCS4 4 246 25.4 22.4 79.5 5 0 0 11268 14026 > HT20 LGI 1 B S MCS5 5 185 30.7 19.7 57.7 5 8 9 3918 9793 > HT20 LGI 1 MCS6 6 164 33.0 0.0 0.0 5 0 0 6 102 > HT20 LGI 1 MCS7 7 148 35.1 0.0 0.0 0 0 0 0 44 > > With the fix: > > best ____________rate__________ ____statistics___ _____last____ ______sum-of________ > mode guard # rate [name idx airtime max_tp] [avg(tp) avg(prob)] [retry|suc|att] [#success | #attempts] > HT20 LGI 1 S MCS0 0 1477 5.6 1.8 28.6 1 0 0 1 5 > HT20 LGI 1 DP MCS1 1 738 10.6 9.7 82.6 4 0 0 14 34 > HT20 LGI 1 MCS2 2 492 14.9 9.2 55.4 5 0 0 52 77 > HT20 LGI 1 B S MCS3 3 369 18.8 15.6 74.9 5 1 1 417 554 > HT20 LGI 1 A MCS4 4 246 25.4 16.7 59.2 5 1 1 13812 17951 > HT20 LGI 1 C S MCS5 5 185 30.7 14.0 41.0 5 1 5 57 640 > HT20 LGI 1 MCS6 6 164 33.0 0.0 0.0 0 0 1 0 48 > HT20 LGI 1 S MCS7 7 148 35.1 0.0 0.0 0 0 0 0 36 > > We can notice the device try now to send with lower rates (and high > success rates). At the end, we measured 20-25% better throughput with > this patch. > > Fixes: 9bca45f3d692 ("staging: wfx: allow to send 802.11 frames") > Tested-by: Olivier Souloumiac > Tested-by: Alexandr Suslenko > Reported-by: Alexandr Suslenko > Co-developed-by: Jérôme Pouiller > Signed-off-by: Jérôme Pouiller > Signed-off-by: Felipe Negrelli Wolter Patch applied to wireless-next.git, thanks. ea2274ab0b18 wifi: wfx: fix case where rates are out of order -- https://patchwork.kernel.org/project/linux-wireless/patch/20231004123039.157112-1-jerome.pouiller@silabs.com/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches