From patchwork Sun May 30 09:58:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kiszka X-Patchwork-Id: 12288151 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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 8710DC47089 for ; Sun, 30 May 2021 10:06:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E74061005 for ; Sun, 30 May 2021 10:06:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229579AbhE3KHr (ORCPT ); Sun, 30 May 2021 06:07:47 -0400 Received: from gecko.sbs.de ([194.138.37.40]:35904 "EHLO gecko.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229500AbhE3KHq (ORCPT ); Sun, 30 May 2021 06:07:46 -0400 X-Greylist: delayed 407 seconds by postgrey-1.27 at vger.kernel.org; Sun, 30 May 2021 06:07:45 EDT Received: from mail2.sbs.de (mail2.sbs.de [192.129.41.66]) by gecko.sbs.de (8.15.2/8.15.2) with ESMTPS id 14U9wufY030721 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 30 May 2021 11:58:56 +0200 Received: from [167.87.72.222] ([167.87.72.222]) by mail2.sbs.de (8.15.2/8.15.2) with ESMTP id 14U9wtEv030019; Sun, 30 May 2021 11:58:55 +0200 From: Jan Kiszka Subject: [PATCH] watchdog: iTCO_wdt: Account for rebooting on second timeout To: Wim Van Sebroeck , Guenter Roeck Cc: linux-watchdog@vger.kernel.org, Linux Kernel Mailing List , Paolo Bonzini , Christian Storm , Andy Shevchenko Message-ID: <73a36792-28f8-e513-b384-bdbe7d31ca05@siemens.com> Date: Sun, 30 May 2021 11:58:55 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org From: Jan Kiszka This was already attempted to fix via 1fccb73011ea: If the BIOS did not enable TCO SMIs, the timer definitely needs to trigger twice in order to cause a reboot. If TCO SMIs are on, we can continue to assume that the BIOS will perform a reboot on the first timeout. QEMU with its ICH9 and related BIOS falls into the former category, currently taking twice the configured timeout in order to reboot the machine. For iTCO version that fall under turn_SMI_watchdog_clear_off, this is also true and was currently only addressed for v1, irrespective of the turn_SMI_watchdog_clear_off value. Signed-off-by: Jan Kiszka --- drivers/watchdog/iTCO_wdt.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c index bf31d7b67a69..091797d12146 100644 --- a/drivers/watchdog/iTCO_wdt.c +++ b/drivers/watchdog/iTCO_wdt.c @@ -71,6 +71,7 @@ #define TCOBASE(p) ((p)->tco_res->start) /* SMI Control and Enable Register */ #define SMI_EN(p) ((p)->smi_res->start) +#define TCO_EN (1 << 13) #define TCO_RLD(p) (TCOBASE(p) + 0x00) /* TCO Timer Reload/Curr. Value */ #define TCOv1_TMR(p) (TCOBASE(p) + 0x01) /* TCOv1 Timer Initial Value*/ @@ -355,8 +356,11 @@ static int iTCO_wdt_set_timeout(struct watchdog_device *wd_dev, unsigned int t) tmrval = seconds_to_ticks(p, t); - /* For TCO v1 the timer counts down twice before rebooting */ - if (p->iTCO_version == 1) + /* + * If TCO SMIs are off, the timer counts down twice before rebooting. + * Otherwise, the BIOS generally reboots when the SMI triggers. + */ + if (p->smi_res && !(SMI_EN(p) & TCO_EN)) tmrval /= 2; /* from the specs: */ @@ -521,7 +525,7 @@ static int iTCO_wdt_probe(struct platform_device *pdev) * Disables TCO logic generating an SMI# */ val32 = inl(SMI_EN(p)); - val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */ + val32 &= ~TCO_EN; /* Turn off SMI clearing watchdog */ outl(val32, SMI_EN(p)); }