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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 25DF2C3A5A2 for ; Fri, 23 Aug 2019 06:51:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 01AAA22CEC for ; Fri, 23 Aug 2019 06:51:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404122AbfHWGvp (ORCPT ); Fri, 23 Aug 2019 02:51:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51642 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732321AbfHWGvo (ORCPT ); Fri, 23 Aug 2019 02:51:44 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 957FE2A09BB; Fri, 23 Aug 2019 06:51:44 +0000 (UTC) Received: from localhost (unknown [10.43.2.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id DA2562633B; Fri, 23 Aug 2019 06:51:43 +0000 (UTC) Date: Fri, 23 Aug 2019 08:51:41 +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 v2] rt2x00: do not set IEEE80211_TX_STAT_AMPDU_NO_BACK on tx status Message-ID: <20190823065141.GA10462@redhat.com> References: <20190712103228.17658-1-sgruszka@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190712103228.17658-1-sgruszka@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 23 Aug 2019 06:51:44 +0000 (UTC) Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Fri, Jul 12, 2019 at 12:32:28PM +0200, Stanislaw Gruszka wrote: > According to documentation IEEE80211_TX_STAT_AMPDU_NO_BACK is suppose > to be used when we do not receive 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 recent changes in rt2x00 removing the flag has no effect on > those test cases. > > So remove the IEEE80211_TX_STAT_AMPDU_NO_BACK. > > Additionally partially mimic mt76 behaviour: send BAR when > starting/stopping BA session to workaround problems with some buggy > clients. Do not sent BAR on PS wakeup since we lack all PS handling > code what mt76 has. Currently Felix posted patch that removed sending BAR on BA session stop. And I do not see necessity for sending BAR on start, so I will precede with first version of this patch, that just remove NO_BACK flag. Stanislaw