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 06B3AC352A5 for ; Mon, 10 Feb 2020 10:16:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DCC5D20842 for ; Mon, 10 Feb 2020 10:16:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727505AbgBJKQu (ORCPT ); Mon, 10 Feb 2020 05:16:50 -0500 Received: from mx2.suse.de ([195.135.220.15]:43592 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727499AbgBJKQu (ORCPT ); Mon, 10 Feb 2020 05:16:50 -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 790F3ACCA; Mon, 10 Feb 2020 10:16:48 +0000 (UTC) Date: Mon, 10 Feb 2020 11:16:38 +0100 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 Subject: wdat_wdt: access width inconsistency Message-ID: <20200210111638.64925c8e@endymion> Organization: SUSE Linux X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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, I'm still working on my customer issue where the wdat_wdt driver reboots the server instantly as soon as the watchdog daemon is started. I looked at all the upstream fixes and we already have all relevant ones in our kernel so I start suspecting either a driver bug or a BIOS issue. While reading the driver code I noticed one suspect thing related to the register access width, which I'd like a second opinion on. Both acpi_watchdog.c and wdat_wdt.c contain code like: res.end = res.start + gas->access_width - 1; This suggests that gas->access_width is expected to be 4 in case of a 32-bit register. However in wdat_wdt_read/wdat_wdt_write we have: switch (gas->access_width) { (...) case 3: *value = ioread32(instr->reg); This looks inconsistent to me. My reading of the ACPI specification suggests that 3 is the right value for 32-bit registers. If so, then shouldn't the resource's end be set to: res.end = res.start + (1 << (gas->access_width - 1)) - 1; ? Thanks, -- Jean Delvare SUSE L3 Support