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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 B4327C11D2F for ; Mon, 24 Feb 2020 10:37:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F62E20732 for ; Mon, 24 Feb 2020 10:37:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727374AbgBXKhd (ORCPT ); Mon, 24 Feb 2020 05:37:33 -0500 Received: from mga18.intel.com ([134.134.136.126]:33499 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726452AbgBXKhd (ORCPT ); Mon, 24 Feb 2020 05:37:33 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Feb 2020 02:37:32 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,479,1574150400"; d="scan'208";a="231091385" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga008.fm.intel.com with ESMTP; 24 Feb 2020 02:37:29 -0800 Received: from andy by smile with local (Exim 4.93) (envelope-from ) id 1j6B7D-004McT-Se; Mon, 24 Feb 2020 12:37:31 +0200 Date: Mon, 24 Feb 2020 12:37:31 +0200 From: Andy Shevchenko To: Mika Westerberg Cc: Guenter Roeck , Martin Volf , Jean Delvare , Wolfram Sang , linux-i2c@vger.kernel.org, linux-hwmon@vger.kernel.org, Linux Kernel Mailing List , Jarkko Nikula Subject: Re: [regression] nct6775 does not load in 5.4 and 5.5, bisected to b84398d6d7f90080 Message-ID: <20200224103731.GA10400@smile.fi.intel.com> References: <1bdbac08-86f8-2a57-2b0d-8cd2beb2a1c0@roeck-us.net> <85356d1a-f90d-e94d-16eb-1071d4e94753@roeck-us.net> <20200224101800.GJ2667@lahna.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200224101800.GJ2667@lahna.fi.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 24, 2020 at 12:18:00PM +0200, Mika Westerberg wrote: > On Sat, Feb 22, 2020 at 01:26:48PM -0800, Guenter Roeck wrote: > > On 2/22/20 12:49 PM, Martin Volf wrote: > > > On Sat, Feb 22, 2020 at 8:05 PM Guenter Roeck wrote: ... > > > devfn = PCI_DEVFN(PCI_SLOT(pci_dev->devfn), 2); I'm wondering if pci_dev_is_present(...); returns false here. > > > pci_bus_read_config_dword(pci_dev->bus, devfn, ACPIBASE, &base_addr); > > > > > > res = &tco_res[ICH_RES_IO_SMI]; > > > res->start = (base_addr & ~1) + ACPIBASE_SMI_OFF; > > > res->end = res->start + 3; > > > res->flags = IORESOURCE_IO; > > > > > > base_addr is 0xffffffff after pci_bus_read_config_dword() call. > > > ACPIBASE_SMI_OFF is 0x030, therefore res->start is 0x2e. > > > Not that I understand even a bit of this... > > > > > > > Outch. This means that the code is broken. ACPIBASE is not configured, > > or disabled, or the code reads from the wrong PCI configuration register. > > What I don't understand is why this works with v5.3 kernels; the code > > looks just as bad there for me. I must be missing something. Either case, > > the only thing you can really do at this point is to blacklist the > > iTCO_wdt driver. > > Indeed it looks like the code reads from a register that is not there > anymore in this generation hardware, or something like that. It tries to > read the PMC (1f.2) register add address 0x40 which is supposed to be > base of ACPI PM registers but that does not seem to exist any more in > newer chipset. > > We'll look into this more and return back. -- With Best Regards, Andy Shevchenko