From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail1.windriver.com (mail1.windriver.com [147.11.146.13]) by mail.openembedded.org (Postfix) with ESMTP id 21F4460017 for ; Fri, 22 Jan 2016 05:29:42 +0000 (UTC) Received: from ALA-HCA.corp.ad.wrs.com (ala-hca.corp.ad.wrs.com [147.11.189.40]) by mail1.windriver.com (8.15.2/8.15.1) with ESMTPS id u0M5Thj1012235 (version=TLSv1 cipher=AES128-SHA bits=128 verify=FAIL) for ; Thu, 21 Jan 2016 21:29:43 -0800 (PST) Received: from [128.224.162.134] (128.224.162.134) by ALA-HCA.corp.ad.wrs.com (147.11.189.50) with Microsoft SMTP Server id 14.3.248.2; Thu, 21 Jan 2016 21:29:42 -0800 To: Randy MacLeod , References: <1453255296-6863-1-git-send-email-rongqing.li@windriver.com> <56A162A5.1000802@windriver.com> From: Rongqing Li Message-ID: <56A1BE45.3040900@windriver.com> Date: Fri, 22 Jan 2016 13:29:41 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <56A162A5.1000802@windriver.com> Subject: Re: [PATCH] watchdog: enable systemd support X-BeenThere: openembedded-core@lists.openembedded.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Patches and discussions about the oe-core layer List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 22 Jan 2016 05:29:45 -0000 Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit On 2016年01月22日 06:58, Randy MacLeod wrote: > On 2016-01-19 09:01 PM, rongqing.li@windriver.com wrote: >> 1. inherit systemd, and add two unit files which are from Fedora 23 > > Fine. >> 2. auto load soft dog kernel module > > I haven't used a hardware watchdog for a while. Does softdog > abstract that away so that it's hidden by the BSP? If not, > can a user ditch the softdog for a hardware watchdog? Does that > over-ride process need to be documented? > > Usually, watchdog timers are implemented as add-on cards, or as on-chip peripherals within microcontrollers. But if there is no hardware watchdog, the Linux kernel can provide a software watchdog implemented using kernel timers. https://en.wikibooks.org/wiki/The_Linux_Kernel/Softdog_Driver if the machine has the hardware watchdog, and drivers are compiled in, the /dev/watchdog will be generated; softdog is /dev/watchdog1 or /dev/watchdog2, and the watchdog daemon will use the hardware watchdog if drivers are compiled as module, udev will auto load it, but udev will be run after systemd-modules-load.service, and softdog will be used -- Best Reagrds, Roy | RongQing Li