From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753293AbbLRRuU (ORCPT ); Fri, 18 Dec 2015 12:50:20 -0500 Received: from bh-25.webhostbox.net ([208.91.199.152]:36948 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752459AbbLRRuT (ORCPT ); Fri, 18 Dec 2015 12:50:19 -0500 Subject: Re: [char-misc-next v2 7/7] watchdog: mei_wdt: re-register device on event To: One Thousand Gnomes References: <1450363780-30008-1-git-send-email-tomas.winkler@intel.com> <1450363780-30008-8-git-send-email-tomas.winkler@intel.com> <56743CD9.3000708@roeck-us.net> <20151218171939.57bf5621@lxorguk.ukuu.org.uk> Cc: Tomas Winkler , Greg Kroah-Hartman , Wim Van Sebroeck , Alexander Usyskin , linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org From: Guenter Roeck Message-ID: <56744757.2060101@roeck-us.net> Date: Fri, 18 Dec 2015 09:50:15 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <20151218171939.57bf5621@lxorguk.ukuu.org.uk> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: linux@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: linux@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/18/2015 09:19 AM, One Thousand Gnomes wrote: >> I am not really happy about the watchdog device appearing and disappearing >> dynamically. This wreaks havoc with any standard watchdog application. > > Any software that doesn't handle this has been broken for over fifteen > years. We have hotplug PCI and we have PCI watchdog card support. This > isn't a new behaviour to anyone outside the embedded single board space. > >> Isn't there a better way to handle this ? How about just registering the >> watchdog device and return an error in the access functions if it is disabled ? > > That breaks the existing behaviour of hot pluggable watchdog interfaces > and is different to just about any other device in the kernel. Today with > any desktop or server distribution you can already trivially arrange for > watchdog daemons to start at the point a watchdog is detected dynamically. > Ok, you have a point. Wonder if any distributions are doing that, though. Any idea ? Guenter