From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753406AbaCBAdi (ORCPT ); Sat, 1 Mar 2014 19:33:38 -0500 Received: from terminus.zytor.com ([198.137.202.10]:36797 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753330AbaCBAdh (ORCPT ); Sat, 1 Mar 2014 19:33:37 -0500 Message-ID: <53127C4B.1060505@zytor.com> Date: Sat, 01 Mar 2014 16:33:15 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 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> In-Reply-To: <53127AA7.8040700@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 04:26 PM, Li, Aubrey wrote: >> >> On March 1, 2014 12:21:39 PM PST, Matthew Garrett wrote: >>> if we've hit the keyboard controller and ACPI twice, and the system is still alive, and >>> if we have standard PCI ports, > >>> it doesn't seem like poking them is likely to make anything actively > worse. >> > This is exactly what I'm trying to express. thanks Matt. It doesn't make > anything worse, it makes reboot working on some systems. > > On 2014/3/2 4:26, H. Peter Anvin wrote: >> True... trying cf9_cond with low priority probably makes sense. > > I'm not asking CF9 only, I'm asking all of the known method in reboot.c. > So, BIOS is appliable as well with the same logic and with low priority, > isn't it? > The problem comes in when a method doesn't just not work, but hangs the machine. BIOS *WILL* hang the machine if it doesn't work. CF9 has been known to hang the machine. -hpa