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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED 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 8723EC282C2 for ; Thu, 7 Feb 2019 12:34:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1E2B921907 for ; Thu, 7 Feb 2019 12:34:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=autistici.org header.i=@autistici.org header.b="gth37Jd/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726809AbfBGMec (ORCPT ); Thu, 7 Feb 2019 07:34:32 -0500 Received: from perdizione.investici.org ([94.23.50.208]:29548 "EHLO perdizione.investici.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726799AbfBGMec (ORCPT ); Thu, 7 Feb 2019 07:34:32 -0500 X-Greylist: delayed 1100 seconds by postgrey-1.27 at vger.kernel.org; Thu, 07 Feb 2019 07:34:31 EST Received: from [94.23.50.208] (perdizione [94.23.50.208]) (Authenticated sender: mikefender@cryptolab.net) by localhost (Postfix) with ESMTPSA id 952151401F4; Thu, 7 Feb 2019 12:16:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=autistici.org; s=stigmate; t=1549541767; bh=sjmHY9aDDchQdHcgHW6hvG74vKp73uJ8suoTQLLgwls=; h=Subject:To:Cc:References:From:Date:In-Reply-To; b=gth37Jd/ipy+rDJ/uPemqMYlLQyx0C6t9OkZJo+EDs82CJQmM8vlMl99sBtGI0q1w VoNyGBP3DT9cm/QmluWBIa3Bvxk1nPRLwDEnbYrhqGl15eqc6QJeDam0DmDKvyyri4 NoIWWzp/lzYS7oeHnzmlCfTA7P5vAbQh9sUkJR94= Subject: Re: [PATCH] dell-smm-hwmon.c: Additional temperature sensors To: =?UTF-8?Q?Pali_Roh=c3=a1r?= Cc: Guenter Roeck , linux-hwmon@vger.kernel.org References: <20181207202927.14168-1-michelesr@autistici.org> <20181208005603.11721-1-michelesr@autistici.org> <3f1b847e-2b70-70bb-f5e6-5f68ffbc63ed@roeck-us.net> <20181210105823.xq3mnrlfgdx63etl@pali> From: Michele Sorcinelli Message-ID: <127d6adc-6002-ad28-14bd-1ca475d421c5@autistici.org> Date: Thu, 7 Feb 2019 12:16:06 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20181210105823.xq3mnrlfgdx63etl@pali> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org As far as I know Dell won't help with fixing the SMM layer, they probably changed something starting with firmware version 1.3.0 and they don't wanna release information about it. https://www.hwinfo.com/forum/Thread-Dell-XPS-15-9570-temperatures-not-named-anymore I wonder if something can be done to force the discovery of the sensors in the driver, maybe adding a module option to use i8k_get_temp() as probe method as a workaround, or maybe just forcing that method for this specific model? Let me know your thoughts. Thanks, Michele. On 12/10/18 10:58 AM, Pali Rohár wrote: > On Friday 07 December 2018 20:24:49 Guenter Roeck wrote: >> Anyway, I would like to get some feedback if this can cause regressions >> on systems which don't support that many sensors and maybe report something >> completely different if one tries to read the high-numbered sensors. >> I seem to recall that there was a reason for checking the type and not just >> trying to read sensor values. > > There can be also different problem for sensors which are turned off. > E.g. on notebooks with switchable graphic cards which have included > temperature sensors. When graphic card is turned off, then SMM returns > error when asking for temperature value (for obvious reason). But > temperature type still returns correct value "this is GPU sensors". > > So we cannot replace temp_type check by temp_value check. It introduce > race condition between "starting GPU" and initializing dell-smm hwmon. > Now linux kernel has support for dynamic turning ON/OFF switchable GPU, > so we need to care about these race conditions too. >