From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35206C4338F for ; Mon, 16 Aug 2021 13:13:38 +0000 (UTC) Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 63958632F9 for ; Mon, 16 Aug 2021 13:13:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 63958632F9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=denx.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.denx.de Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id 5D10B82BD6; Mon, 16 Aug 2021 15:13:35 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=none (p=none dis=none) header.from=denx.de Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1629119615; bh=Ub/i78Pmd4I0ddKH1gSIGOq78RLuGS0c614xGJvGsMQ=; h=Subject:To:Cc:References:From:Date:In-Reply-To:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=gI0aLT2+3/36cjTDS1foOTrXl6uglF6pW4muOUrgHkzssE0gBSMDBg9StVfqj0cwp 8w0+XFPU+L/6rJzpEJsYk3Dt3RXWifIhVF0ki4bTR4ulPgMWj4oTfG2EWONqq71hoo 3k/wt/zEuS0FWtRbrydWvS7EfukfN3q6UUywxI8251aOZXvlRGxzCEIEJSGMvJ+pB0 u/Y79RfFRkxaMbHhbAI5CpIAyN2QSoO5mCT7zJcfRHtLA+U3ZUzk/Lfvk15NR7WqQI gFo34Q/RiJbU+qeRJ0xZilOqCBO7PODy/06QqTRIwMmv2QVYfOItXOHHeeKnq8NB4f npFcvykin16VA== Received: by phobos.denx.de (Postfix, from userid 109) id 9138482C28; Mon, 16 Aug 2021 15:13:33 +0200 (CEST) Received: from mout-u-107.mailbox.org (mout-u-107.mailbox.org [IPv6:2001:67c:2050:1::465:107]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by phobos.denx.de (Postfix) with ESMTPS id 7A35582BCE for ; Mon, 16 Aug 2021 15:13:28 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=none (p=none dis=none) header.from=denx.de Authentication-Results: phobos.denx.de; spf=fail smtp.mailfrom=sr@denx.de Received: from smtp2.mailbox.org (smtp2.mailbox.org [IPv6:2001:67c:2050:105:465:1:2:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-u-107.mailbox.org (Postfix) with ESMTPS id 4GpF3D1prTzQkJC; Mon, 16 Aug 2021 15:13:28 +0200 (CEST) Received: from smtp2.mailbox.org ([80.241.60.241]) by spamfilter03.heinlein-hosting.de (spamfilter03.heinlein-hosting.de [80.241.56.117]) (amavisd-new, port 10030) with ESMTP id wwBPyILDDS1Y; Mon, 16 Aug 2021 15:13:25 +0200 (CEST) Subject: Re: [PATCH u-boot-mvebu 3/3] arm: mvebu: turris_omnia: disable MCU watchdog in SPL when booting over UART To: =?UTF-8?Q?Marek_Beh=c3=ban?= Cc: u-boot@lists.denx.de, pali@kernel.org References: <20210816122726.14506-1-marek.behun@nic.cz> <20210816122726.14506-4-marek.behun@nic.cz> <446b9f6d-70d0-04fc-ea4c-edbd876a194e@denx.de> <20210816150140.5a622211@dellmb> <20210816151100.0d9e7cc0@dellmb> From: Stefan Roese Message-ID: <753289ee-911f-1476-591e-fe2249b2f505@denx.de> Date: Mon, 16 Aug 2021 15:13:25 +0200 MIME-Version: 1.0 In-Reply-To: <20210816151100.0d9e7cc0@dellmb> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 727E91846 X-Rspamd-UID: d6b1fc X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.34 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" X-Virus-Scanned: clamav-milter 0.103.2 at phobos.denx.de X-Virus-Status: Clean On 16.08.21 15:11, Marek Behún wrote: > On Mon, 16 Aug 2021 15:07:33 +0200 > Stefan Roese wrote: > >> So the MCU watchdog is some kind of very early WD and only used until >> the SoC WD is used / enabled? > > Yes, this is how it was first thought of for Omnia. Looking at the MCU > code it seems that the watchdog can be started again after being > disabled, so it could theoretically be used as a normal watchdog. The > problem is that it cannot be pinged to reset the counter. It has to be > stopped and started again, meaning there is a small window when it is > disabled. If the system used this watchdog, this small window would > make it vulnerable, so I don't think we should use it. Agreed. With such a WD concept including this "window of vulnerability", it really shouldn't be used. Thanks, Stefan >>> Shall I resend this series with this new patch? > >> Yes, please do. > > Will do. > > Marek > Viele Grüße, Stefan -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email: sr@denx.de