From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: Regression: Recent networking (qdisc?) patches break irda_get_next_speed() Date: Tue, 21 Oct 2008 21:37:37 +0200 Message-ID: <48FE2F81.9060801@gmail.com> References: <48FE1D52.6080903@ceibo.fiec.espol.edu.ec> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev@vger.kernel.org To: =?ISO-8859-1?Q?Alex_Villac=ED=ADs_Lasso?= Return-path: Received: from nf-out-0910.google.com ([64.233.182.191]:40422 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751315AbYJUTgs (ORCPT ); Tue, 21 Oct 2008 15:36:48 -0400 Received: by nf-out-0910.google.com with SMTP id d3so1257039nfc.21 for ; Tue, 21 Oct 2008 12:36:46 -0700 (PDT) In-Reply-To: <48FE1D52.6080903@ceibo.fiec.espol.edu.ec> Sender: netdev-owner@vger.kernel.org List-ID: Alex Villac=ED=ADs Lasso wrote, On 10/21/2008 08:20 PM: > A regression has been introduced in 2.6.27 in the networking code, wh= ich=20 > breaks the irda_get_next_speed() function used by some IrDA drivers,=20 > including ks959-sir, written by me. I have filed a bug at: >=20 > http://bugzilla.kernel.org/show_bug.cgi?id=3D11795 >=20 > to keep track of this. I am still performing bisection to locate the=20 > exact commit that broke the code, but the bug involves an overwriting= of=20 > the beginning of a structure with extraneous data that makes the=20 > LAP_MAGIC check fail. I have tried searching the netdev archives, but= =20 > there is no mention at all of regressions caused by this code. Milan=20 > Plzik at irda-users mentions the same problem affecting pxaficp_ir, a= nd=20 > mentions recent qdisc patches as possible culprits. Vasily Khoruzhic= k=20 > reported this bug at irda-users, and a quick hack (not a proper fix)=20 > proposed by him involves padding "struct irda_skb_cb" with 4 bytes at= =20 > the beginning of the structure to move everything else past the buggy= =20 > scribbling. Looks like the patch below could fit to your description. Jarek P. commit 175f9c1bba9b825d22b142d183c9e175488b260c Author: Jussi Kivilinna Date: Sun Jul 20 00:08:47 2008 -0700 net_sched: Add size table for qdiscs Add size table functions for qdiscs and calculate packet size in qdisc_enqueue(). Based on patch by Patrick McHardy http://marc.info/?l=3Dlinux-netdev&m=3D115201979221729&w=3D2 Signed-off-by: Jussi Kivilinna Signed-off-by: David S. Miller