Return-path: Received: from py-out-1112.google.com ([64.233.166.181]:36130 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754745AbXILIk4 (ORCPT ); Wed, 12 Sep 2007 04:40:56 -0400 Received: by py-out-1112.google.com with SMTP id u77so281249pyb for ; Wed, 12 Sep 2007 01:40:55 -0700 (PDT) Message-ID: <1ba2fa240709120140l56c21269p8254c790edda42b1@mail.gmail.com> Date: Wed, 12 Sep 2007 11:40:55 +0300 From: "Tomas Winkler" To: "Ulrich Kunitz" Subject: Re: zd-mac80211: Fix TX status reports. Cc: "Johannes Berg" , "Michael Buesch" , "Daniel Drake" , "John Linville" , linux-wireless@vger.kernel.org In-Reply-To: <20070911223258.GA31400@deine-taler.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 References: <200709082341.31720.mb@bu3sch.de> <200709111220.31700.mb@bu3sch.de> <1189506596.6161.14.camel@johannes.berg> <200709111252.30291.mb@bu3sch.de> <1189508230.6161.18.camel@johannes.berg> <20070911223258.GA31400@deine-taler.de> Sender: linux-wireless-owner@vger.kernel.org List-ID: On 9/12/07, Ulrich Kunitz wrote: > Johannes Berg wrote: > > > On Tue, 2007-09-11 at 12:52 +0200, Michael Buesch wrote: > > > On Tuesday 11 September 2007 12:29:56 Johannes Berg wrote: > > > > On Tue, 2007-09-11 at 12:20 +0200, Michael Buesch wrote: > > > > > > > > > What about the following: > > > > > We have a "the packet failed" IRQ. so we know that if that didn't > > > > > raise for a packet, it must have succeed. > > > > > So currently we already maintain a queue of TX packets. What about > > > > > changing the handling of this queue? Instead of dropping (and > > > > > telling mac80211 success) on an ACK RX, simply do a timeout. > > > > > We can calculate the time (plus some additional msecs to be sure) > > > > > by when an ACK must have arrived, no? > > > > > > > > That's tricky though, because multiple retry rates mean that it can > > > > possibly take quite a while for the packet to go through. And ath5k > > > > wants to support up to 7 different rates for each packet. > > > > > > I'm only talking about zd, though. > > > > Yeah, but that means the driver should implement it because it has much > > less problems getting the heuristics right. > > Notify that the TX-failed interrupt has only the destination MAC > address of the transmitted packet. So if the driver has sent two packets > to the device and both are still in their timeout time, it will > not be known, whether the first or the second failed. (The > destination address for STAs will always be the same.) > > Sending only one packet until the timeout period is over is > certainly doable and could be used for critical activity like > association and authentication, but for normal mode the driver > should only be required to provide statistics. > That was my suggestion as well. > -- > Uli Kunitz >