Return-path: Received: from mail-qw0-f46.google.com ([209.85.216.46]:54361 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751398Ab1HYMie (ORCPT ); Thu, 25 Aug 2011 08:38:34 -0400 Received: by qwk3 with SMTP id 3so1236964qwk.19 for ; Thu, 25 Aug 2011 05:38:34 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <1314265865-20208-1-git-send-email-arik@wizery.com> From: Arik Nemtsov Date: Thu, 25 Aug 2011 15:38:19 +0300 Message-ID: (sfid-20110825_143837_970237_519987A2) Subject: Re: [PATCH 1/2] mac80211: add flag to indicate HW only Tx-agg support To: Helmut Schaa Cc: linux-wireless@vger.kernel.org, Luciano Coelho , Johannes Berg Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, Aug 25, 2011 at 15:18, Helmut Schaa wrote: > Hi, > > On Thu, Aug 25, 2011 at 11:51 AM, Arik Nemtsov wrote: >> When this flag is set, Tx aggregations will not be initiated even >> if the hardware supports A-MPDU aggregation in general. This flag >> is required for devices supporting (partial) software Rx-aggregation. > > Is the hardware unable to do TX aggregation? > Or is it just not implemented? > Or is it entirely done in hw? Tx aggregations are done entirely in HW. > > Instead of cluttering mac80211 with hw flags you could also just disallow tx > aggregation sessions in the ampdu_action callback in the driver. Well the driver is doing some pretty heavy lifting before even calling the ampdu_action callback. Namely, ieee80211_start_tx_ba_session() doesn't call it. AFAICT, the return from the callback is only used as an indication that Tx BA session are temporary unavailable, and mac80211 should try again. This is not the case here. Regards, Arik