From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from bu3sch.de ([62.75.166.246]:42085 "EHLO vs166246.vserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754054AbYGIPPs (ORCPT ); Wed, 9 Jul 2008 11:15:48 -0400 From: Michael Buesch To: Ivo van Doorn Subject: Re: [PATCH 1/3] mac80211: Include sequence number in IBSS and Mesh beacons Date: Wed, 9 Jul 2008 17:15:24 +0200 Cc: Johannes Berg , "John W. Linville" , linux-wireless@vger.kernel.org, rt2400-devel@lists.sourceforge.net References: <200807091511.14288.IvDoorn@gmail.com> <1215614895.3246.17.camel@johannes.berg> <200807091708.04870.IvDoorn@gmail.com> In-Reply-To: <200807091708.04870.IvDoorn@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Message-Id: <200807091715.24710.mb@bu3sch.de> (sfid-20080709_171600_600517_AF9400C5) Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wednesday 09 July 2008 17:08:04 Ivo van Doorn wrote: > On Wednesday 09 July 2008, Johannes Berg wrote: > > > > > If rt2x00 would use a global lock to block all TX and beacons, then yes. > > > But rt2x00 uses per-queue locking. When a beacon is being updated rt2x00 > > > will still allow regular frames to be queued. > > > > That just widens the window. And if you have multiple queues then you > > can't do sw sequence numbers anyway because the hardware might reorder > > the frames. > > That doesn't seem to be a problem in the legacy drivers, so I guess the hardware > does *something* to prevent problems. Well, legacy drivers don't use mac80211. Sequence counting can trivially be fixed by doing it _right_ before queueing the packet to the hardware in the driver, with the TX queue lock held, that must already be there. -- Greetings Michael.