From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754487Ab0CGPRA (ORCPT ); Sun, 7 Mar 2010 10:17:00 -0500 Received: from mailrelay007.isp.belgacom.be ([195.238.6.173]:34737 "EHLO mailrelay007.isp.belgacom.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754362Ab0CGPQ6 (ORCPT ); Sun, 7 Mar 2010 10:16:58 -0500 X-Belgacom-Dynamic: yes X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AvsEAFtQk0tbstZK/2dsb2JhbACbQ3S3Yg2EawQ Date: Sun, 7 Mar 2010 16:16:56 +0100 From: Wim Van Sebroeck To: Simon Kagstrom Cc: linux-kernel@vger.kernel.org, seth.heasley@intel.com Subject: Re: [PATCH] iTCO_wdt: Don't stop on shutdown with nowayout Message-ID: <20100307151656.GX7459@infomag.iguana.be> References: <20100223164019.60a6de1a@marrow.netinsight.se> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100223164019.60a6de1a@marrow.netinsight.se> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, > Currently, the watchdog is turned off when the system shuts down or the > module is unloaded. If nowayout has been selected, this makes no sense > and fails to restart the system if it hangs during reboot, so make it > conditional. the nowayout option is there to make sure that the watchdog keeps running as long as the system is running. If you however do a system shutdown (which means that you are going to reboot your server in a controlled fasion and thus not as result of a crash or hang-situation), then either the shutdown function of your platform_driver or the reboot_notifier call will be executed. In the case of a watchdog device idriver we will then stop the watchdog to prevent reboot's during the fsck that might happen after reboot. If you run into a reboot operation during an fsck then chances a very big that after the reboot your system will again be rebooted during the next fsck. To prevent this fsck-reboot-loop issue we turn of the watchdog when rebooting. Because of this, I'm not going to apply this patch. > We have a system which has such a hang, and therefore want the watchdog > to be on until the bitter end. Hmm, the correct question here should be: why do we have a hang in a clean boot. Do you have more info on what exactly happens? This might be an initialization problem. If we better understand what happens, then we might consider having an option to keep the watchdog on after a reboot (which has nothing to do with the nowayout functionality imho). or even power-on. Kind regards, Wim.