From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753219Ab0BYHpm (ORCPT ); Thu, 25 Feb 2010 02:45:42 -0500 Received: from ernst.netinsight.se ([194.16.221.21]:10155 "HELO ernst.netinsight.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752908Ab0BYHpl convert rfc822-to-8bit (ORCPT ); Thu, 25 Feb 2010 02:45:41 -0500 Date: Thu, 25 Feb 2010 08:45:35 +0100 From: Simon Kagstrom To: =?ISO-8859-1?Q?P=E1draig?= Brady Cc: Wim Van Sebroeck , linux-kernel@vger.kernel.org Subject: Re: [PATCH] iTCO_wdt: Don't double the requested timeout Message-ID: <20100225084535.4658cbf9@marrow.netinsight.se> In-Reply-To: <4B854F58.4050907@draigBrady.com> References: <20100223164019.60a6de1a@marrow.netinsight.se> <4B840154.1010501@draigBrady.com> <4B840BC6.9090809@draigBrady.com> <20100224101618.39c3468b@marrow.netinsight.se> <4B84FD15.9020803@draigBrady.com> <20100224124730.6958b2c0@marrow.netinsight.se> <4B8545D1.8000302@draigBrady.com> <20100224165526.61cdd169@marrow.netinsight.se> <4B854F58.4050907@draigBrady.com> X-Mailer: Claws Mail 3.7.4 (GTK+ 2.16.1; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (taking back lkml on CC. The discussion is about stopping watchdogs before rebooting). On Wed, 24 Feb 2010 16:10:00 +0000 Pádraig Brady wrote: > > Returning to the initial issue (my patch to avoid stopping the watchdog > > before reboot): What is the preferred behavior? I've looked in other > > drivers, and see multiple ways being used. Some do as in my patch, some > > leave it on unconditionally and some stop it unconditionally. > > > Well nowayout to me means userspace should have no way out, > but when rebooting the system the watchdog should be reset. > But in saying that I'm not sure what to do. At least there > should be some way to select the operation you want above, > so as to protect the reboot process itself. Well, from the drives I saw that had this behavior (not that I checked all of them), they did look at nowayout to determine whether to stop it or not. > In general, I wonder could an order be specified so that > the watchdog is disabled as the very last thing by the kernel, > right before it does the reboot? Many other drivers use reboot notifiers, but unfortunately it seems that these are called before device shutdown (kernel/sys.c), so it wouldn't help here. I guess it would be good to have defined and uniform behavior across different watchdogs, and at least an option to specify nowayout-also-when-rebooting. // Simon