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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 9390DC352A2 for ; Wed, 5 Feb 2020 15:05:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 75DF3217F4 for ; Wed, 5 Feb 2020 15:05:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726678AbgBEPFd (ORCPT ); Wed, 5 Feb 2020 10:05:33 -0500 Received: from mx2.suse.de ([195.135.220.15]:45282 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726592AbgBEPFc (ORCPT ); Wed, 5 Feb 2020 10:05:32 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id C99C0AD11; Wed, 5 Feb 2020 15:05:30 +0000 (UTC) Message-ID: <1580915129.23547.3.camel@suse.de> Subject: Forcing non-ACPI watchdog driver From: Jean Delvare To: "Rafael J. Wysocki" Cc: Len Brown , linux-acpi@vger.kernel.org, Wim Van Sebroeck , Guenter Roeck , linux-watchdog@vger.kernel.org, Mika Westerberg , Tom Abraham Date: Wed, 05 Feb 2020 16:05:29 +0100 Organization: Suse Linux Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Hi all, Is there a way to prevent the ACPI WDAT watchdog interface from being used and force the use of a native watchdog driver instead? I have a customer who reports a regression on kernel upgrade. Old kernel (v4.4) uses iTCO_wdt and watchdog works, new kernel (v4.12) uses wdat_wdt and watchdog doesn't work (instant reboot when opening the device). While I'm going to look for fixes to backport, I think it would be pretty convenient to have a way to just revert to the working driver until the new driver is fixed somehow. But I can't see any way to do that at the moment, short of disabling ACPI completely, which is definitely too extreme to be considered. Am I missing something? Thanks, -- Jean Delvare SUSE L3 Support