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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 1BB80C38BE1 for ; Mon, 24 Feb 2020 18:27:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8D7920838 for ; Mon, 24 Feb 2020 18:27:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="FSrPnF7a" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727954AbgBXS1e (ORCPT ); Mon, 24 Feb 2020 13:27:34 -0500 Received: from mail-pg1-f194.google.com ([209.85.215.194]:39382 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726208AbgBXS1d (ORCPT ); Mon, 24 Feb 2020 13:27:33 -0500 Received: by mail-pg1-f194.google.com with SMTP id j15so5573358pgm.6; Mon, 24 Feb 2020 10:27:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=MrKUG0B7eYSk1M5khvLuZNq23j1QXcVre857FpjhTKQ=; b=FSrPnF7avWq6iRs7cohi5j4rz+s7j/Tj0f88zgou8HhnYzaSubzRiNGvLDDxomSnoz tOKCrVYoJ1uXY0Oi8+sGL1TTp8YiyhTpkTBAC0XUeJU32M4WBTWfDHU/8eJVkClk9AVa Lc2WB4xLIXNFlPSQ9kX1i/ZgubMsWMAsNb7llvf3jpDduZR0MfbeLevVxgCD76f6/Ow/ qIat1DOsl9nIs0S8N1oyS4IBd7vqOt3NeLeT/UNiVrttL+0ChhvJ40p2mrBOw2DMrjvA DVI29E8VpSnZrIygiPSgzv9BOSjkw00RZhVr2TZe3c4/oYtdsLligV2PmhwkDDM6R8Tn aUKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=MrKUG0B7eYSk1M5khvLuZNq23j1QXcVre857FpjhTKQ=; b=tAsBZ7A/pOB4ET5CzudmTS6w3MS8z5UwTkzLhTjlhbxjJgKzzJXkrzP2iatNeQ85TM 62YoTBN5CeElb29b4I5rUJEegH4MN/0bxeXa4yoYJ4k8utn+PtRktnzxLd5Hq392vArL zpAYt8paqYSZu/QDaYD+88CBcbUf+NnCjvFtE50hCy/or72sienDuPktm77f7/6iZHX+ toP0gFX1aDHGVZbbF0WhgEgKbeRPKQKmTYxwUFEPA7fKG1lmbD0VC7PeRic/SlFKJlm9 IxJExNk46wRHDHvG9e1LLLMXtJli5r8NlIE3b46cB2M8nnUqB+QhboDKO1Si2wExZnKU WfFA== X-Gm-Message-State: APjAAAVs4qWDG/BBmq8sz/sWxPakKd++pKLykI+BIrYsuMm4RoGZuxBc JBmWuqNk7p7i8eRKqmP239A= X-Google-Smtp-Source: APXvYqxiMX24zB+DtpsxWet1mWC8XeyWPZMsc08gR6Ns5FCq3fO5jmw6lLtSEWXSrn2ZlFO7OHzPxw== X-Received: by 2002:a62:7541:: with SMTP id q62mr52672610pfc.248.1582568852748; Mon, 24 Feb 2020 10:27:32 -0800 (PST) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id 70sm13434909pgd.28.2020.02.24.10.27.31 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 24 Feb 2020 10:27:31 -0800 (PST) Date: Mon, 24 Feb 2020 10:27:30 -0800 From: Guenter Roeck To: Mika Westerberg Cc: Andy Shevchenko , 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: <20200224182730.GA29799@roeck-us.net> References: <1bdbac08-86f8-2a57-2b0d-8cd2beb2a1c0@roeck-us.net> <85356d1a-f90d-e94d-16eb-1071d4e94753@roeck-us.net> <20200224101800.GJ2667@lahna.fi.intel.com> <20200224103731.GA10400@smile.fi.intel.com> <20200224105121.GK2667@lahna.fi.intel.com> <20200224112740.GL2667@lahna.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200224112740.GL2667@lahna.fi.intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) 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 01:27:40PM +0200, Mika Westerberg wrote: > On Mon, Feb 24, 2020 at 12:51:25PM +0200, Mika Westerberg wrote: > > > I'm wondering if > > > > > > pci_dev_is_present(...); > > > > > > returns false here. > > > > Well that might also be the case since lspci shows this: > > > > 00:1f.0 ISA bridge: Intel Corporation Z390 Chipset LPC/eSPI Controller (rev 10) > > 00:1f.3 Audio device: Intel Corporation Cannon Lake PCH cAVS (rev 10) > > 00:1f.4 SMBus: Intel Corporation Cannon Lake PCH SMBus Controller (rev 10) > > > > PMC is 1f.2 and not present here. However, it may be that the PMC is > > still there it just does not "enumerate" because its devid/vendorid are > > set to 0xffff. Similar hiding was done for the P2SB bridge. > > Actually I think this is the case here. > > I don't know the iTCO_wdt well enough to say if it could live without > the ICH_RES_IO_SMI. It looks like this register is used to disable SMI > generation but not sure how well it works if it is left to BIOS to > configure. I suppose these systems should use WDAT instead. > In practice the region is only used if if (turn_SMI_watchdog_clear_off >= p->iTCO_version) { where turn_SMI_watchdog_clear_off is 1 by default. It is also passed to vendor specific code, but that is only relevant for really old systems. In short, it isn't really needed for any recent-generation systems, and could be made optional with a few lines of code in iTCO_wdt.c. Guenter