From owner-freebsd-bugs@FreeBSD.ORG Tue Mar 28 19:10:29 2006 Return-Path: X-Original-To: freebsd-bugs@hub.freebsd.org Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 642BA16A401 for ; Tue, 28 Mar 2006 19:10:29 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id AB2CB43D58 for ; Tue, 28 Mar 2006 19:10:23 +0000 (GMT) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.13.4/8.13.4) with ESMTP id k2SJANwO009769 for ; Tue, 28 Mar 2006 19:10:23 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.13.4/8.13.4/Submit) id k2SJANwB009768; Tue, 28 Mar 2006 19:10:23 GMT (envelope-from gnats) Date: Tue, 28 Mar 2006 19:10:23 GMT Message-Id: <200603281910.k2SJANwB009768@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org From: Nate Lawson Cc: Subject: Re: kern/94939: [acpi] [patch] reboot(8) fails on IBM / Intel blades X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Nate Lawson List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Mar 2006 19:10:29 -0000 The following reply was made to PR kern/94939; it has been noted by GNATS. From: Nate Lawson To: John Baldwin Cc: bug-followup@freebsd.org, dodell@ixsystems.com Subject: Re: kern/94939: [acpi] [patch] reboot(8) fails on IBM / Intel blades Date: Tue, 28 Mar 2006 11:08:02 -0800 John Baldwin wrote: > Nate, > > I'm curious where you think this code should go if not here? I'd imagine > we don't want to do this after AcpiTerminate() since perhaps the specified > register may no longer be available (I might be wrong though, I haven't > checked the spec). > I don't have a specific idea since I didn't look at it closely. I think there might be some requirements of writes to the reset register (delays, expectation of chipset configuration, order with other shutdown tasks). Here are the requirements from the spec: >>> 4.7.3.6 Reset Register The optional ACPI reset mechanism specifies a standard mechanism that provides a complete system reset. When implemented, this mechanism must reset the entire system. This includes processors, core logic, all buses, and all peripherals. From an OSPM perspective, asserting the reset mechanism is the logical equivalent to power cycling the machine. Upon gaining control after a reset, OSPM will perform actions in like manner to a cold boot. ... The system must reset immediately following the write to this register. OSPM assumes that the processor will not execute beyond the write instruction. OSPM should execute spin loops on the CPUs in the system following a write to this register. >>> So I'm ok with the patch being committed if no other tasks need to happen after this shutdown handler is called. Also, all APs should be stopped before this happens and it should only occur once on the BSP. -- Nate