Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753699AbaDDRhi (ORCPT ); Fri, 4 Apr 2014 13:37:38 -0400 Received: from terminus.zytor.com ([198.137.202.10]:51200 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752998AbaDDRhh (ORCPT ); Fri, 4 Apr 2014 13:37:37 -0400 User-Agent: K-9 Mail for Android In-Reply-To: <20140404173431.GA25173@gmail.com> References: <533D8516.1040803@zytor.com> <20140403121314.246b03a7@gandalf.local.home> <533DED74.6050202@linux.intel.com> <20140403194018.7c67aec7@gandalf.local.home> <533DF455.4040908@linux.intel.com> <533DF8D2.9060508@zytor.com> <533E0A94.5040007@linux.intel.com> <20140404151203.GA12370@srcf.ucam.org> <533ECC2C.6090505@zytor.com> <20140404153634.GA14519@srcf.ucam.org> <20140404173431.GA25173@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Subject: Re: [BUG] x86: reboot doesn't reboot From: "H. Peter Anvin" Date: Fri, 04 Apr 2014 10:37:07 -0700 To: Ingo Molnar , Matthew Garrett CC: "Li, Aubrey" , Steven Rostedt , Linus Torvalds , LKML , Thomas Gleixner Message-ID: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The comment header is bogus... it describes what we do, not what Windows does. On April 4, 2014 10:34:31 AM PDT, Ingo Molnar wrote: > >* Matthew Garrett wrote: > >> On Fri, Apr 04, 2014 at 08:13:48AM -0700, H. Peter Anvin wrote: >> > On 04/04/2014 08:12 AM, Matthew Garrett wrote: >> > > On Fri, Apr 04, 2014 at 09:27:48AM +0800, Li, Aubrey wrote: >> > > >> > >> The current situation is, >> > >> - we have one(do we know more?) preproduction machine hangs by >CF9. >> > >> - We have more than one(could be thousand known) production >machine >> > >> works by CF9. >> > > >> > > Production hardware should never require CF9. >> > > >> > >> > There are a lot of things that shouldn't be. >> >> Windows doesn't hit CF9, and production hardware is always tested >with >> Windows, so. [...] > >So why the hell does the reboot function comment claim that the >Windows reboot sequence (which is the de facto hardware standard) >uses 0xcf9: > >/* > * Windows compatible x86 hardware expects the following on reboot: > * > * 1) If the FADT has the ACPI reboot register flag set, try it > * 2) If still alive, write to the keyboard controller > * 3) If still alive, write to the ACPI reboot register again > * 4) If still alive, write to the keyboard controller again > * 5) If still alive, call the EFI runtime service to reboot > * 6) If still alive, write to the PCI IO port 0xCF9 to reboot > * 7) If still alive, inform BIOS to do a proper reboot > * > >?? > >Thanks, > > Ingo -- Sent from my mobile phone. Please pardon brevity and lack of formatting. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/