From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752639AbcEDQRe (ORCPT ); Wed, 4 May 2016 12:17:34 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:43464 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750846AbcEDQRd (ORCPT ); Wed, 4 May 2016 12:17:33 -0400 Subject: Re: [PATCH RFC] Watchdog: sbsa_gwdt: Enhance timeout range To: Pratyush Anand Cc: Guenter Roeck , fu.wei@linaro.org, Suravee.Suthikulpanit@amd.com, wim@iguana.be, linux-arm-kernel@lists.infradead.org, linux-watchdog@vger.kernel.org, open list , Dave Young , Wim Van Sebroeck References: <20da73bb9bdf27993514c1da80fead13dc92932d.1462262900.git.panand@redhat.com> <5728A7C3.4010001@roeck-us.net> <20160503143856.GE13045@dhcppc6.redhat.com> <5728BEC4.6050603@codeaurora.org> <20160503155141.GF13045@dhcppc6.redhat.com> <20160503171602.GA2518@roeck-us.net> <20160504141449.GG13045@dhcppc6.redhat.com> <572A0577.1070000@codeaurora.org> <20160504155932.GH13045@dhcppc6.redhat.com> From: Timur Tabi Message-ID: <572A2099.4070901@codeaurora.org> Date: Wed, 4 May 2016 11:17:29 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:43.0) Gecko/20100101 Firefox/43.0 SeaMonkey/2.40 MIME-Version: 1.0 In-Reply-To: <20160504155932.GH13045@dhcppc6.redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Pratyush Anand wrote: > Its unique to SBSA because you have very little timeout here. kexec-tools > upstream does not have any mechanism to handle watchdog timeout. Lets say even > if we implement a framework there, the best it can do is to ping the watchdog > again. Ok, so it's more accurate to say that kexec has a minimum watchdog timeout requirement. What happens if the system admin sets the timeout to 5 seconds arbitrarily? The system will reset during kexec, no matter which hardware is used. This still sounds like a band-aid to me. We're just assuming that we need a timeout of at least 20 seconds to support kexec. Frankly, this still sounds like a problem the kexec developers needs to acknowledge and deal with. Still I'm okay with a patch that extends the timeout by programming WCV, but it has to be commented as a hack specifically to support kexec because the timeout might be too short. Then Wim can decide whether he supports such changes. -- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation collaborative project.