From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from xc.sipsolutions.net ([83.246.72.84]:41334 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755244AbYEDMsg (ORCPT ); Sun, 4 May 2008 08:48:36 -0400 Subject: Re: mac80211 truesize bugs From: Johannes Berg To: Herbert Xu Cc: David Miller , mb@bu3sch.de, netdev@vger.kernel.org, linux-wireless@vger.kernel.org In-Reply-To: <20080504124542.GA1455@gondor.apana.org.au> References: <1209866916.6210.39.camel@johannes.berg> <20080504021213.GA30660@gondor.apana.org.au> <1209867740.6210.46.camel@johannes.berg> <20080504031652.GA30993@gondor.apana.org.au> <1209890847.6210.51.camel@johannes.berg> <1209892489.6210.56.camel@johannes.berg> <20080504094444.GA541@gondor.apana.org.au> <1209894754.6210.58.camel@johannes.berg> <1209900355.6210.64.camel@johannes.berg> <1209904088.4065.11.camel@johannes.berg> <20080504124542.GA1455@gondor.apana.org.au> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-pT1LkiG4nSlouIyW10iU" Date: Sun, 04 May 2008 14:48:23 +0200 Message-Id: <1209905303.4065.20.camel@johannes.berg> (sfid-20080504_144802_561821_BB795C04) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-pT1LkiG4nSlouIyW10iU Content-Type: text/plain Content-Transfer-Encoding: quoted-printable > Right hard_header_len is being overloaded with two meanings. > On the one hand it's used to indicate the length of the header > managed by the hardware header cache, on the other hand we use > it to indicate the head room for those devices that don't have > a cache. >=20 > Since your device wants both, it fails miserably. Yeah I guess that is actually the root cause. > There are three ways out of this. You could have your own cache > (I haven't looked at your headers so I don't know whether that > makes sense), have no cache at all, or add a new field that gets > added to hard_header_len for the purposes of calculating head > room. In fact, I should probably add another field for the needed tail length too since we need that as well. johannes --=-pT1LkiG4nSlouIyW10iU Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIVAwUASB2wlqVg1VMiehFYAQLksQ//UFIWoH5yvL0itxrX+j+HGNHf+yFJHetE 9y5NNQkmnDRhYsCmC/4Zb4x9SICMIcHnnyDZJsfkyeABGfvOIQFohtbLU3GRk1tX m62FZhz8Zd/+R4cy1MgDOBOGlujYEJn07lWOGD8H6eqWpKHcFkakGp3/xjRDcJq+ EeAYED3nKFeecgdptRvBpJVq1K5BmXQWI8TKDI9g1JSTtQPYLbS5S2nX+NrUMMn2 R87KU3jwXGJ/MJLJwopN7CBg5mmrUJfK9Irz1HpCeWCwcHA7vHU5V5tMicNXArzC Bmtb2ygBbEho7V/3MyipThSSIR6/+JIShOEQup9pa1dmutNv/qXeIzK6cooMn3Hk 6a2D5nl2iMRkFQFs/hJ0IzHue/5aqXvsskHrWlDgZ/tPY0yCAgQa/LW1/UJY61nb c3QY+7eOYyAWMqvxLxyMTyx3VfJC6qUyIzAK/2KYVKWHU427xDL+TSs1v3IrD5IL m+y3A07hZ9Co34vqbJERNlt2bhg19YTbgoPZL/f0KMC6RFQ333nWUlM8YUDoJGze vahVHbuOaWfE85MmzpvfNhkGrOsGi/uat5VLERs7JaSnoriIMiFzPleydGu4ux+E KkjbUdFJuLopMjwrbCUtIEhAQ/zDUHV4/E91gWYCV1eqEhZtGSiIRTVbxAfL7Lv+ ZtCxA/ZsOzc= =h0N6 -----END PGP SIGNATURE----- --=-pT1LkiG4nSlouIyW10iU--