From owner-freebsd-hackers@FreeBSD.ORG Tue May 26 15:39:17 2009 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 57EE61065678 for ; Tue, 26 May 2009 15:39:17 +0000 (UTC) (envelope-from glen.j.barber@gmail.com) Received: from mail-bw0-f213.google.com (mail-bw0-f213.google.com [209.85.218.213]) by mx1.freebsd.org (Postfix) with ESMTP id D47F78FC1C for ; Tue, 26 May 2009 15:39:16 +0000 (UTC) (envelope-from glen.j.barber@gmail.com) Received: by bwz9 with SMTP id 9so3988375bwz.43 for ; Tue, 26 May 2009 08:39:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=rZk06YrQB8cbGQv+o2PFuIqs7HeiccPxoSbiKtm/+j4=; b=ubiN4LJT3KpN6YBVboewskTNd/GfIDq/PsdgiOuq+MHeKKbDNH5w5NBC4dnHJJwQBj jUzE/J9fia1gDoQZ9YejaSmqftcqYa6H4N2TjAy09SBdOyFCrsW4dVl3rBLWBl+kyXxE A6iXHRR53g3QDUU5fhKgxyN/TIEwcCiQ8cMyQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=mTFkVUej9DpIZPgB9RkSufEOOnbAJOd/T29ncvNbUzw/uW2miIMW/wqVkHq/VhO+MF yVndgvCKA4/h9qsllQLnN4366S4G3CfQKHmuVHaQgBjzas/NQyjh3fHBII4/6MOvKYYg oDoDysStTUhQhtcTunQLpLk+DO4eKrWwBFo/8= MIME-Version: 1.0 Received: by 10.223.121.6 with SMTP id f6mr4503856far.77.1243352355285; Tue, 26 May 2009 08:39:15 -0700 (PDT) In-Reply-To: <1243345847.1007.11.camel@nebet.ii.uam.es> References: <1243345847.1007.11.camel@nebet.ii.uam.es> Date: Tue, 26 May 2009 11:39:15 -0400 Message-ID: <4ad871310905260839u24ce71e9wbaa637712480c390@mail.gmail.com> From: Glen Barber To: =?ISO-8859-1?Q?Fernando_Herrero_Carr=F3n?= Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd-hackers@freebsd.org Subject: Re: Help debugging kernel together with X X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 26 May 2009 15:39:17 -0000 Hi, Fernando 2009/5/26 Fernando Herrero Carr=F3n : > Hi list, > > I would like to ask for some help debugging the kernel. > > Here is the problem: > > I have a computer about five years old with an on-board graphics card > (SiS 661). I am trying to install an ATI Radeon 128 on the AGP port. > FreeBSD (FreeBSD 7.2-STABLE #10: Tue May 26 15:08:39 CEST 2009) is able > to start DRM and AGP without trouble. However, whenever I start X (X.Org > X Server 1.6.1; Release Date: 2009-4-14; Build Date: 11 May 2009 > 12:03:27PM) the system freezes with a blank screen with some apparent > noisy green dots on it (reproducible, however). It does not panic, nor > reboot. > > Now I suspect there is some problem on the AGP bridge driver since linux > can run X without trouble (i.e. hardware and BIOS are ok). I have found > someone reporting problems with this bridge long time ago with no > answers (http://www.nabble.com/agp-on-sis-661-td1446998.html). > > So here I am trying to figure out where the system freezes. I have > recompiled my kernel adding the following options: > > options =A0 =A0 =A0 =A0 KDB > options =A0 =A0 =A0 =A0 DDB > options =A0 =A0 =A0 =A0 MP_WATCHDOG > options =A0 =A0 =A0 =A0 SW_WATCHDOG > > I am able to enter the debugger with ctrl+alt+esc from a console. So > what I am trying to do is to have watchdogd time out and the debugger > make a dump: > > ddb script kern.enter.watchdog=3Dcall doadump; reboot > > However, when I start X no timeout occurs, and the system stays freezed. > Am I missing something on the workings of watchdogd? > What you're describing does not appear to be a kernel problem; it sounds like the typical 'Xorg update from hell' problem most experienced a while back. Have a look at /usr/ports/UPDATING, and search for 'AllowEmptyInput'. Adding the following to xorg.conf should correct the problem: Section "ServerFlags" option "AllowEmptyInput" "off" option "AutoAddDevices" "off" EndSection HTH --=20 Glen Barber