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 X-Spam-Level: X-Spam-Status: No, score=-7.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02197C742B2 for ; Fri, 12 Jul 2019 10:25:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB6FF2064B for ; Fri, 12 Jul 2019 10:25:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726128AbfGLKZN (ORCPT ); Fri, 12 Jul 2019 06:25:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36730 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726050AbfGLKZM (ORCPT ); Fri, 12 Jul 2019 06:25:12 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5EFBC81F10; Fri, 12 Jul 2019 10:25:12 +0000 (UTC) Received: from localhost (ovpn-204-58.brq.redhat.com [10.40.204.58]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9AB281001B2B; Fri, 12 Jul 2019 10:25:11 +0000 (UTC) Date: Fri, 12 Jul 2019 12:25:10 +0200 From: Stanislaw Gruszka To: linux-wireless@vger.kernel.org Cc: Tomislav =?utf-8?Q?Po=C5=BEega?= , Daniel Golle , Felix Fietkau , Mathias Kresin Subject: Re: [RFC/RFT] rt2x00: do not set IEEE80211_TX_STAT_AMPDU_NO_BACK on tx status Message-ID: <20190712102510.GA17258@redhat.com> References: <20190704110652.3955-1-sgruszka@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190704110652.3955-1-sgruszka@redhat.com> User-Agent: Mutt/1.11.3 (2019-02-01) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Fri, 12 Jul 2019 10:25:12 +0000 (UTC) Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Thu, Jul 04, 2019 at 01:06:52PM +0200, Stanislaw Gruszka wrote: > According to documentation IEEE80211_TX_STAT_AMPDU_NO_BACK is suppose > to be used when we do not recive BA (BlockAck). However on rt2x00 we > use it when remote station fail to decode one or more subframes within > AMPDU (some bits are not set in BlockAck bitmap). Setting the flag result > in sent of BAR (BlockAck Request) frame and this might result of abuse > of BA session, since remote station can sent BA with incorrect > sequence numbers after receiving BAR. This problem is visible especially > when connecting two rt2800 devices. > > Previously I observed some performance benefits when using the flag > when connecting with iwlwifi devices. But currently possibly due > to reacent changes in rt2x00 removing the flag has no effect on > those test cases. > > So remove the IEEE80211_TX_STAT_AMPDU_NO_BACK. > > Perhaps we should send BAR exlicitly on BA session start/stop > and when remote STA went to PowerSave mode (for AP) like mt76 does. > But I do not understand for what this is needed. This commit https://github.com/openwrt/mt76/commit/3e447e7797d64dbf4dc1dd5553d08be0d8150d7e explained that sending BAR on stop aggregation is workaround for buggy clients. I can implement that on rt2x00. But I will skip sending BAR on remote station PS wakeup, since we do not implement all PS related code in rt2x00. Stanislaw