From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756086AbXKXWUq (ORCPT ); Sat, 24 Nov 2007 17:20:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752613AbXKXWUj (ORCPT ); Sat, 24 Nov 2007 17:20:39 -0500 Received: from smtp-106-saturday.nerim.net ([62.4.16.106]:53848 "EHLO kraid.nerim.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752550AbXKXWUi (ORCPT ); Sat, 24 Nov 2007 17:20:38 -0500 Date: Sat, 24 Nov 2007 23:20:35 +0100 From: Jean Delvare To: Michael Buesch Cc: benh@kernel.crashing.org, Roger Leigh , linux-kernel@vger.kernel.org, Dennis Munsie Subject: Re: radeonfb i2c regression post-2.6.18. Message-ID: <20071124232035.0f46d530@hyperion.delvare> In-Reply-To: <200711241518.26755.mb@bu3sch.de> References: <1195427766.7022.18.camel@pasglop> <200711231700.53103.mb@bu3sch.de> <20071123232928.467378a7@hyperion.delvare> <200711241518.26755.mb@bu3sch.de> X-Mailer: Sylpheed-Claws 2.5.5 (GTK+ 2.10.6; x86_64-suse-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 24 Nov 2007 15:18:26 +0100, Michael Buesch wrote: > On Friday 23 November 2007 23:29:28 Jean Delvare wrote: > > Out of curiosity, what kind of crash was it? I admit that I can't see > > how the code could crash. > > It's not the code that crashes. It's the hardware that turns off the machine. > It only happens if I boot the machine and only if it's hot at this > time. Some hardware will turn off the hardware two or three seconds > after the radeon driver was loaded. > It seems to be some overheating protection that's going crazy. Very strange indeed. Another possibility is that there is a hardware monitoring chip connected to one of the Radeon adapter's I2C buses, and that holding the I2C lines prevents reading from it, so whatever is responsible for controlling the temperature prefers to play it safe and shuts everything down. Somehow it seems more realistic than an actual overheating (3 seconds is a very short period of time for that), but we'd need the exact schematics of the hardware, and the details of the thermal control system, to validate this theory. Anyway, no need to worry anymore now that the bug is fixed :) -- Jean Delvare