Return-path: Received: from s3.sipsolutions.net ([144.76.43.152]:59411 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753148Ab3JAKWf (ORCPT ); Tue, 1 Oct 2013 06:22:35 -0400 Message-ID: <1380622952.14430.9.camel@jlt4.sipsolutions.net> (sfid-20131001_122238_089954_44F2CFE1) Subject: Re: [PATCH] mac80211: support reporting A-MSDU subframes individually From: Johannes Berg To: Michal Kazior Cc: linux-wireless@vger.kernel.org Date: Tue, 01 Oct 2013 12:22:32 +0200 In-Reply-To: <1379943278-1014-1-git-send-email-michal.kazior@tieto.com> References: <1379943278-1014-1-git-send-email-michal.kazior@tieto.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, 2013-09-23 at 15:34 +0200, Michal Kazior wrote: > Some devices may not be able to report A-MSDUs in > single buffers. Drivers for such devices were > forced to re-assemble A-MSDUs which would then > be eventually disassembled by mac80211. This could > lead to CPU cache thrashing and poor performance. > > Since A-MSDU has a single sequence number all > subframes share it. This was in conflict with > retransmission/duplication recovery > (IEEE802.11-2012: 9.3.2.10). > > Patch introduces a new flag that is meant to be > set for all individually reported A-MSDU subframes > except the last one. This ensures the > last_seq_ctrl is updated after the last subframe > is processed. If an A-MSDU is actually a duplicate > transmission all reported subframes will be > properly discarded. Applied. johannes