From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from ey-out-2122.google.com ([74.125.78.25]:48492 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751778AbZHES5r (ORCPT ); Wed, 5 Aug 2009 14:57:47 -0400 Received: by ey-out-2122.google.com with SMTP id 9so215939eyd.37 for ; Wed, 05 Aug 2009 11:57:47 -0700 (PDT) From: Ivo van Doorn To: Johannes Berg Subject: Re: mac80211 TX frame alignment Date: Wed, 5 Aug 2009 20:57:45 +0200 Cc: linux-wireless@vger.kernel.org References: <200908041905.11632.IvDoorn@gmail.com> <1249407436.24787.6.camel@johannes.local> In-Reply-To: <1249407436.24787.6.camel@johannes.local> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Message-Id: <200908052057.45715.IvDoorn@gmail.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi, > > Do you know if for outgoing frames the header should always > > be 4-byte aligned? > > I know that there's no alignment guarantee. > > > I have a bugreport from users claiming that master mode > > is failing for rt2500pci because the beacons passed to the > > driver are not 4-byte aligned which causes the device not > > to send out the beacons correctly. > > > > I'm just wondering if this is something that should be fixed > > in the driver or in mac80211. > > I don't think we can fix that in mac80211, since we don't know whether > or not any alignment is required. We could align beacon frames, I > suppose, since those are created on the fly, but not data frames. Ok, I'll look into a patch for making sure rt2x00 aligns all frames correctly before mapping the DMA. Thanks, Ivo