From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753444AbaCBCHk (ORCPT ); Sat, 1 Mar 2014 21:07:40 -0500 Received: from terminus.zytor.com ([198.137.202.10]:37316 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753373AbaCBCHj (ORCPT ); Sat, 1 Mar 2014 21:07:39 -0500 Message-ID: <53129256.6060704@zytor.com> Date: Sat, 01 Mar 2014 18:07:18 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: "Li, Aubrey" , Matthew Garrett CC: "H. Peter Anvin" , "alan@linux.intel.com" , linux-kernel@vger.kernel.org, Len.Brown@intel.com, Adam Williamson Subject: Re: [patch] x86: Introduce BOOT_EFI and BOOT_CF9 into the reboot sequence loop References: <53102AB9.40600@linux.intel.com> <20140228062325.GA3246@srcf.ucam.org> <53102F3C.4020806@linux.intel.com> <20140228064413.GA4900@srcf.ucam.org> <531032A0.8090903@linux.intel.com> <5310CBB7.4030407@linux.intel.com> <53110977.8080907@linux.intel.com> <53121496.8060603@linux.intel.com> <20140301172256.GA29417@srcf.ucam.org> <53123DCF.7040500@zytor.com> <20140301202139.GA9759@srcf.ucam.org> <53127AA7.8040700@linux.intel.com> <53127C4B.1060505@zytor.com> <53128DA0.9060105@linux.intel.com> In-Reply-To: <53128DA0.9060105@linux.intel.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/01/2014 05:47 PM, Li, Aubrey wrote: > > Since we are not able to make things worse, let's make it better. So > Let's dig into this. For the machine hangs by CF9, it's known to work by > KBD, right? For the machine hangs by BIOS, do you know which method will > make reboot work? > No. > The answer will determine the sequence of the list. If BIOS hangs but > either of ACPI/KBD/EFI/CF9 works, BIOS is behind of those ways. If BIOS > hangs, no any other way can make it work. BIOS is still the last way. > > If CF9 hangs while ACPI/KBD hangs as well, and BIOS happened to work(do > we really have one?), the above list still doesn't make things worse, > reboot=b and dmidecode table still work. We obviously have been over this a number of times, and the sad thing is that we have very limited information. It is more complex than that, even... I believe in some cases KBD works but it is slow, and so takes a while. -hpa