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=-4.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 387ABC433B4 for ; Mon, 19 Apr 2021 06:06:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EAD3761104 for ; Mon, 19 Apr 2021 06:06:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233650AbhDSGGq (ORCPT ); Mon, 19 Apr 2021 02:06:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229652AbhDSGGo (ORCPT ); Mon, 19 Apr 2021 02:06:44 -0400 Received: from mail-lf1-x12a.google.com (mail-lf1-x12a.google.com [IPv6:2a00:1450:4864:20::12a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90AEEC06174A; Sun, 18 Apr 2021 23:06:15 -0700 (PDT) Received: by mail-lf1-x12a.google.com with SMTP id i10so18196316lfe.11; Sun, 18 Apr 2021 23:06:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:subject:to:message-id:date:user-agent:mime-version :content-language:content-transfer-encoding; bh=Qk+RkRzDC2RxMA9iVtxLQ0qZjKIyiZ7SI3o9mYd7cUA=; b=pCLU7XvjOqCkEHHV3MkifI+9WYJuQX8/wVTrBOE7x5Imxbn1c6gHnVMbCz+ip1igqx qWX5bzOYp6kW2kN1/4KadR3iBMlYER/05Yaj7YoeXtSNsNzsJCYvMe01Mse++X+MVHAS n2+23ov9dURUhAM8RJl6vRIwXbTQf1jkPoas7GdBRL4Js00hJIWo1F6IkQO9FJ8dcyZ8 WUbS3uzQv2o81yevvTDd1Ahe3d9EbMY8AP0GpC7z7zxx05KavZdWGexipLYBMGdBvRAN X4w0YpfbNcAHXHJNTg0Jay8+0LGXuupdpdOXCOec1SFFkuYBmuVVKU+rDDtVRFQkbKF6 ezGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:subject:to:message-id:date:user-agent :mime-version:content-language:content-transfer-encoding; bh=Qk+RkRzDC2RxMA9iVtxLQ0qZjKIyiZ7SI3o9mYd7cUA=; b=aeKTihapjKAIA9hxzhKN510onbSdPyYbrqFOiXS8FWv3Nw+bH/vXna8ckPH6CtEgEa tVVxrUe6fESHL6HB0/0gQpfVudf1KSLfbds0RbOTdO/Lx1yunKgtEfBN8JQk7cq5nwXp fWQT23SZQk3W6w3zTUDdD8CGn1/9b7aVrFBAr57cbNc+nl4NJZht4WLnsPKozd7GiEOw b6xYY8Z46oIsvP1ZmBnEGVF6s0FBGC++Kl2xyNgrc5Beeahd+4jPeFsCpXg76TK1MTWN Q+ppuqhbSixSjsqHUWm7lt2fsyNN0EI/3lEspt7FjEWLLcJpncYKkNK64k5eXKBu4LPe CuvQ== X-Gm-Message-State: AOAM531xRz7d9Dc0iIStgjFL5rOr2BkbTcacZFqsOtJa6NjgEqEV0tU1 tYVHPYQfdIrOUOpOdJfg+z1OoLLAF6k= X-Google-Smtp-Source: ABdhPJxDdgAoLEZe1YRYBSsAOnIKMJwZH5RNdcoqdiRKASztvqv2zRCq4Y762ISnDyLceIqur6dI7g== X-Received: by 2002:a05:6512:1286:: with SMTP id u6mr10847235lfs.377.1618812374061; Sun, 18 Apr 2021 23:06:14 -0700 (PDT) Received: from [192.168.2.145] (109-252-193-103.dynamic.spd-mgts.ru. [109.252.193.103]) by smtp.googlemail.com with ESMTPSA id c11sm973332ljr.70.2021.04.18.23.06.13 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 18 Apr 2021 23:06:13 -0700 (PDT) From: Dmitry Osipenko Subject: BUG: iio: mpu3050: Wrong temperature scale To: Linus Walleij , Jonathan Cameron , "linux-iio@vger.kernel.org" , Linux Kernel Mailing List , Svyatoslav Ryhel Message-ID: <483ac17b-705a-38c3-54ee-7f0089262c03@gmail.com> Date: Mon, 19 Apr 2021 09:06:13 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Svyatoslav and me found that the MPU3050 IIO driver reports temperature that is x10 larger than it should be on Asus Transformer TF201 and Acer A500 tablet devices running mainline kernel. The driver uses (x+23000)/280 formula for the conversion of raw temperature value, which gives 82C for x=0, thus apparently formula is wrong because x=50000 should give us ~25C. I tried to search for the datasheet with the formula, but couldn't find it. Linus, will you be able to check whether the formula used by the driver is correct? Thanks in advance.