Return-path: Received: from xc.sipsolutions.net ([83.246.72.84]:41005 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750886AbZJaI4J (ORCPT ); Sat, 31 Oct 2009 04:56:09 -0400 Subject: Re: ieee80211_tx_status: headroom too small From: Johannes Berg To: Ivo van Doorn Cc: Nikolai ZHUBR , linux-wireless@vger.kernel.org In-Reply-To: <200910310951.30016.IvDoorn@gmail.com> References: <1094614475.20091030230028@mail.ru> <7111590175.20091031005644@mail.ru> <1256967967.3555.71.camel@johannes.local> <200910310951.30016.IvDoorn@gmail.com> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-IIfdre/l0wvo7z5MElmA" Date: Sat, 31 Oct 2009 09:56:10 +0100 Message-ID: <1256979370.3555.91.camel@johannes.local> Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-IIfdre/l0wvo7z5MElmA Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sat, 2009-10-31 at 09:51 +0100, Ivo van Doorn wrote: > > Ok. I looked at the problem and it's a very odd problem -- mac80211 > > should always reserve enough headroom in buffers it passes to the > > driver. Does rt61pci somehow realloc frames? >=20 > It does use skb_push. but will/should always stay within the limits > of rt2x00dev->hw->extra_tx_headroom. Although I just realize there > might be a situation where it needs to align the frame to a 4-byte bounda= ry, > it could exceed that amount. :( extra_tx_headroom is set to max_t(driver, mac80211) so that there's always some headroom. This doesn't take into account alignment though. Should we simply add 2 to that value? johannes --=-IIfdre/l0wvo7z5MElmA Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- iQIcBAABAgAGBQJK6/unAAoJEODzc/N7+QmagDUP/3q85+WV/UPB86mKdNIIy17+ lbiO0lplxH1PUpnwM5Uq7CJAYyxFfleHaPtqY234jkly8fOgfZVpA4S8hyZNj6Gq HyPsNdXS2GTnukyZ01unYIQJTqBgE8iesCNWjTc4s7vhGTbx/34gBGuPNVckW94G n7JGsV9fZ2u0OV8ht79gVTl1jZHzO+/VjuUqcWY6wkwlhEDZKAEiIV4qxK+IrNZt BQk9Qi5GHBlac5h3DvrGZRpaLyVXkhcQcrtvLwF+vrbSUrn285Ibg3Da0JfBFZJE up7mttOy7GixphB+AlkJ07QGknX8VRkCLEZba8fKuTvezLdQk3VFvlhNL6mkH2bp 5XJdVt+T5slK8DDtm3ZQFlMn2j1LK0zxy1qmt8himC12E/Gz73v+Es3orxWP44zK FdedeUEoeJTeACUdYA8/dmmPJBKA61C1B2UMliLrhcCdFg8WuSYtjdsqq1Rf2cTT AkFOOuOiWxoD2MKsx1s95PI/XEg/HJZKKUmeFAkLC3GmRrRuYrHaKrvoStIebi8/ IeCgycfscCpDMmf3UTEfiRcwB2hXowokGoFVfGLMcuYbN9jMiPJP7n/YkClkAajD IdOtDK1xkQF/uXuYJe3NkVX42RCjTYJU2qhYmteV8MNSfEqZN0+hGltVnjo+YWPj dgxVLcPSce85Vr9VdRvP =yS51 -----END PGP SIGNATURE----- --=-IIfdre/l0wvo7z5MElmA--