From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932957AbdEVTox (ORCPT ); Mon, 22 May 2017 15:44:53 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:46880 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751038AbdEVTov (ORCPT ); Mon, 22 May 2017 15:44:51 -0400 Date: Mon, 22 May 2017 12:44:48 -0700 From: Guenter Roeck To: Alan Cox Cc: Rasmus Villemoes , linux-watchdog@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Sebastian Reichel , esben.haabendal@gmail.com Subject: Re: [PATCH v5 0/3] watchdog: allow setting deadline for opening /dev/watchdogN Message-ID: <20170522194448.GA29867@roeck-us.net> References: <1495462000-28979-1-git-send-email-rasmus.villemoes@prevas.dk> <20170522190751.5bf5e813@alans-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170522190751.5bf5e813@alans-desktop> User-Agent: Mutt/1.5.24 (2015-08-30) X-Authenticated_sender: guenter@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: guenter@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: guenter@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 Mon, May 22, 2017 at 07:07:51PM +0100, Alan Cox wrote: > On Mon, 22 May 2017 16:06:36 +0200 > Rasmus Villemoes wrote: > > > If a watchdog driver tells the framework that the device is running, > > the framework takes care of feeding the watchdog until userspace opens > > the device. If the userspace application which is supposed to do that > > never comes up properly, the watchdog is fed indefinitely by the > > kernel. This can be especially problematic for embedded devices. > > > > These patches allow one to set a maximum time for which the kernel > > will feed the watchdog, thus ensuring that either userspace has come > > up, or the board gets reset. This allows fallback logic in the > > bootloader to attempt some recovery (for example, if an automatic > > update is in progress, it could roll back to the previous version). > > > This makes sense except for being a CONFIG_ option not a boot parameter. > If it's a boot parameter then the same kernel works for multiple systems > and is general. If it's compile time then you have to build a custom > kernel. > > For some embedded stuff that might not matter (although I bet they'd > prefer it command line/device tree too) but for something like an x86 > platform where you are deploying a standard vendor supplied kernel it's > bad to do it that way IMHO. > > In other words I think you should drop patch 3 but the rest is good. > Same here. Can we assume a formal Reviewed-by: from you for the first two patches ? Thanks, Guenter > Alan > -- > To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html