Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752309AbbHEI1a (ORCPT ); Wed, 5 Aug 2015 04:27:30 -0400 Received: from metis.ext.pengutronix.de ([92.198.50.35]:60071 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751437AbbHEI13 (ORCPT ); Wed, 5 Aug 2015 04:27:29 -0400 Date: Wed, 5 Aug 2015 10:27:21 +0200 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= To: Guenter Roeck Cc: =?iso-8859-1?Q?P=E1draig?= Brady , linux-watchdog@vger.kernel.org, Wim Van Sebroeck , linux-kernel@vger.kernel.org, Timo Kokkonen , linux-doc@vger.kernel.org, Jonathan Corbet , kernel@pengutronix.de Subject: Re: [PATCH 0/8] watchdog: Add support for keepalives triggered by infrastructure Message-ID: <20150805082721.GY9999@pengutronix.de> References: <1438654414-29259-1-git-send-email-linux@roeck-us.net> <55C14E2B.1080904@draigBrady.com> <20150805073605.GW9999@pengutronix.de> <55C1C041.3080504@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <55C1C041.3080504@roeck-us.net> User-Agent: Mutt/1.5.21 (2010-09-15) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1182 Lines: 29 Hello Guenter, On Wed, Aug 05, 2015 at 12:50:25AM -0700, Guenter Roeck wrote: > On 08/05/2015 12:36 AM, Uwe Kleine-K?nig wrote: > >the watchdog I'm currently working with on a powerpc platform has a > >unchangable timeout of ~1 s. To make the machine boot I patched the > >bootloader and need some automatic pinging in the kernel before > >userspace takes over. > > > > Does using arch_initcall in the watchdog driver help here, or is that > still too slow and you really need to hack the kernel ? I didn't do any measurements yet, but having the bootloader extracting the kernel, and then send a ping before jumping into it is good enough even without CONFIG_GPIO_WATCHDOG_ARCH_INITCALL to get the machine up. (Userspace doesn't do any watchdog handling yet.) Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/