From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:35980 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754664AbcILR5K (ORCPT ); Mon, 12 Sep 2016 13:57:10 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Date: Mon, 12 Sep 2016 23:27:08 +0530 From: Rajkumar Manoharan To: Johannes Berg Cc: Rajkumar Manoharan , linux-wireless@vger.kernel.org Subject: Re: [PATCH] mac80211: allow driver to handle packet-loss mechanism In-Reply-To: <1473684288.29016.38.camel@sipsolutions.net> References: <20160906065624.4062-1-rmanohar@qti.qualcomm.com> <1473684288.29016.38.camel@sipsolutions.net> Message-ID: (sfid-20160912_195714_835229_9C986B34) Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2016-09-12 18:14, Johannes Berg wrote: > On Tue, 2016-09-06 at 12:26 +0530, Rajkumar Manoharan wrote: >> mac80211 keeps track of missing acks and triggers CQM packet-loss >> mechanism whenever consecutive msdu failure reaches threshold limit >> (STA_LOST_PKT_THRESHOLD). Drivers like ath10k offlaoded rate countrol >> and aggregation to firmware. Such drivers have its own connection >> monitoring algorithm that is offloaded to firmware for triggering >> station kickout due to excessive tries. In VHT mode, single PPDU can >> have >> more than 50 msdus at higher rates. Under noisy environment, single >> ppdu >> failure can cause station kickout by current mac80211 lost_packet >> mechanism >> while firmware is trying to adapt its rate table. This is causing >> frequent >> connect and disconnect iteration when station is roaming around. >> >> In such scenario, driver (or firmware) is not given enough chance to >> tune its rate control. So for devices that report low ack events, add >> a >> hardware flag to rely on their mechnism. >> > > The way you describe this it sounds like somehow you'll be reporting > the indication to userspace from the driver; but you do not, and cannot > do that. The description seems thus misleading? > Sorry for confusion.. The idea is that driver will report low ack status by ieee80211_report_low_ack and if driver wants to completely rely on firmware algorithm, then this flag will be used to bypass mac80211 packet loss mechanism. does it make sense? -Rajkumar