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=-5.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, 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 9BC40C433DB for ; Tue, 9 Mar 2021 05:25:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46DF164ED9 for ; Tue, 9 Mar 2021 05:25:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230084AbhCIFZO (ORCPT ); Tue, 9 Mar 2021 00:25:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229587AbhCIFZC (ORCPT ); Tue, 9 Mar 2021 00:25:02 -0500 Received: from mail-oi1-x231.google.com (mail-oi1-x231.google.com [IPv6:2607:f8b0:4864:20::231]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6ABFFC06174A; Mon, 8 Mar 2021 21:25:02 -0800 (PST) Received: by mail-oi1-x231.google.com with SMTP id z126so13667913oiz.6; Mon, 08 Mar 2021 21:25:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:subject:to:cc:references:from:autocrypt:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=CEnEXEW5f4cRVmLUnX1/3KTWuNFdnKUSfxJrbm3iX/I=; b=i7IPM+OGX+7PMxEx1G/mQK5NuSjGP8HtZQ0ZLhhChBkK6QvBkzRWkJ0RSTNm4SaKEx frjtYCdt9TpYCkwRm8FQMxlj6HBPKQV+Ri6A3UPrjCRiu3R4QcMvlVS6S12riL9EyMsq 04IH9NMyf99WCOMq0w94XSkML3XbNscW7+YBd3KHkNW6eQSlztCkP2YSdzWHKUAUcssJ o1XlYwvjr8FMVeDyMKFrdA4l+3Hqi/XEJ8rhxQ3RAN4OmvXBaXxH++TdJ2pT8JE9+lw3 jPDijGnz+MOjWGIc6Rpm8vQJ88HfpHHjUJ8Zpylh0sz6qM3AX3283naUiPzKaLz5FtvR oWlg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:subject:to:cc:references:from:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=CEnEXEW5f4cRVmLUnX1/3KTWuNFdnKUSfxJrbm3iX/I=; b=uZvFx/Q79Aw6St3jCVQYOrAfqjsGK6H0/KGutp9PvnVuYBPoGOHxdkG1SEEBYjeooJ 6B55tbVlK3VcIe6eY1YR1jRQWT4ojr7Mm7ro4C6gjuGErWfsua+8rDubVGvIhi2gza2M O6czmQ8Ee0E41vFmIhJOjhTm7PiZbR1CUWtap4CaFoeigEVsR0aQ0PVZk/9VmnIJwTDG bpCLtCLw7aq7u1HQH0R/Hxet25eFy+RfNChXUHrsbc0zUoe+8Wn8ZxZ+xDaNwVueTRKe XIidWvBSt2RJ9LZRxJokNJh//XbL1Pt2MAN7gp3aWlcV0/t3gNVGLogU6IIimsuwy4gR JlOg== X-Gm-Message-State: AOAM530LrAj8ZHUHegCuQIT7/ZI9mubz1DDzVDIC8bprAGaoyPYv39Ht WDmATbm52i4AHbOe/QK0WnQmSvLxBIs= X-Google-Smtp-Source: ABdhPJw0IK2W48ZXsHY22vgcfpnSNZcKAb0zkInN0pWS5BwrgeDKjjPKYtIl99nMOkSXRE6stbDaMQ== X-Received: by 2002:aca:4896:: with SMTP id v144mr1747647oia.154.1615267501828; Mon, 08 Mar 2021 21:25:01 -0800 (PST) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id k24sm760637oic.51.2021.03.08.21.24.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 08 Mar 2021 21:25:00 -0800 (PST) Sender: Guenter Roeck Subject: Re: Errant readings on LM81 with T2080 SoC To: Chris Packham , "jdelvare@suse.com" Cc: "linux-hwmon@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-i2c@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" References: <8e0a88ba-01e9-9bc1-c78b-20f26ce27d12@alliedtelesis.co.nz> <96d660bc-17ab-4e0e-9a94-bce1737a8da1@roeck-us.net> <4a1b1494-df96-2d8c-9323-beb2c2ba706b@alliedtelesis.co.nz> <5709f180-04b5-09b2-e1c4-53eb5c9345d8@roeck-us.net> <61f68c59-593b-e393-5520-d9acc14fdf97@alliedtelesis.co.nz> From: Guenter Roeck Autocrypt: addr=linux@roeck-us.net; keydata= xsFNBE6H1WcBEACu6jIcw5kZ5dGeJ7E7B2uweQR/4FGxH10/H1O1+ApmcQ9i87XdZQiB9cpN RYHA7RCEK2dh6dDccykQk3bC90xXMPg+O3R+C/SkwcnUak1UZaeK/SwQbq/t0tkMzYDRxfJ7 nyFiKxUehbNF3r9qlJgPqONwX5vJy4/GvDHdddSCxV41P/ejsZ8PykxyJs98UWhF54tGRWFl 7i1xvaDB9lN5WTLRKSO7wICuLiSz5WZHXMkyF4d+/O5ll7yz/o/JxK5vO/sduYDIlFTvBZDh gzaEtNf5tQjsjG4io8E0Yq0ViobLkS2RTNZT8ICq/Jmvl0SpbHRvYwa2DhNsK0YjHFQBB0FX IdhdUEzNefcNcYvqigJpdICoP2e4yJSyflHFO4dr0OrdnGLe1Zi/8Xo/2+M1dSSEt196rXaC kwu2KgIgmkRBb3cp2vIBBIIowU8W3qC1+w+RdMUrZxKGWJ3juwcgveJlzMpMZNyM1jobSXZ0 VHGMNJ3MwXlrEFPXaYJgibcg6brM6wGfX/LBvc/haWw4yO24lT5eitm4UBdIy9pKkKmHHh7s jfZJkB5fWKVdoCv/omy6UyH6ykLOPFugl+hVL2Prf8xrXuZe1CMS7ID9Lc8FaL1ROIN/W8Vk BIsJMaWOhks//7d92Uf3EArDlDShwR2+D+AMon8NULuLBHiEUQARAQABzTJHdWVudGVyIFJv ZWNrIChMaW51eCBhY2NvdW50KSA8bGludXhAcm9lY2stdXMubmV0PsLBgQQTAQIAKwIbAwYL CQgHAwIGFQgCCQoLBBYCAwECHgECF4ACGQEFAlVcphcFCRmg06EACgkQyx8mb86fmYFg0RAA nzXJzuPkLJaOmSIzPAqqnutACchT/meCOgMEpS5oLf6xn5ySZkl23OxuhpMZTVX+49c9pvBx hpvl5bCWFu5qC1jC2eWRYU+aZZE4sxMaAGeWenQJsiG9lP8wkfCJP3ockNu0ZXXAXwIbY1O1 c+l11zQkZw89zNgWgKobKzrDMBFOYtAh0pAInZ9TSn7oA4Ctejouo5wUugmk8MrDtUVXmEA9 7f9fgKYSwl/H7dfKKsS1bDOpyJlqhEAH94BHJdK/b1tzwJCFAXFhMlmlbYEk8kWjcxQgDWMu GAthQzSuAyhqyZwFcOlMCNbAcTSQawSo3B9yM9mHJne5RrAbVz4TWLnEaX8gA5xK3uCNCeyI sqYuzA4OzcMwnnTASvzsGZoYHTFP3DQwf2nzxD6yBGCfwNGIYfS0i8YN8XcBgEcDFMWpOQhT Pu3HeztMnF3HXrc0t7e5rDW9zCh3k2PA6D2NV4fews9KDFhLlTfCVzf0PS1dRVVWM+4jVl6l HRIAgWp+2/f8dx5vPc4Ycp4IsZN0l1h9uT7qm1KTwz+sSl1zOqKD/BpfGNZfLRRxrXthvvY8 BltcuZ4+PGFTcRkMytUbMDFMF9Cjd2W9dXD35PEtvj8wnEyzIos8bbgtLrGTv/SYhmPpahJA l8hPhYvmAvpOmusUUyB30StsHIU2LLccUPPOwU0ETofVZwEQALlLbQeBDTDbwQYrj0gbx3bq 7kpKABxN2MqeuqGr02DpS9883d/t7ontxasXoEz2GTioevvRmllJlPQERVxM8gQoNg22twF7 pB/zsrIjxkE9heE4wYfN1AyzT+AxgYN6f8hVQ7Nrc9XgZZe+8IkuW/Nf64KzNJXnSH4u6nJM J2+Dt274YoFcXR1nG76Q259mKwzbCukKbd6piL+VsT/qBrLhZe9Ivbjq5WMdkQKnP7gYKCAi pNVJC4enWfivZsYupMd9qn7Uv/oCZDYoBTdMSBUblaLMwlcjnPpOYK5rfHvC4opxl+P/Vzyz 6WC2TLkPtKvYvXmdsI6rnEI4Uucg0Au/Ulg7aqqKhzGPIbVaL+U0Wk82nz6hz+WP2ggTrY1w ZlPlRt8WM9w6WfLf2j+PuGklj37m+KvaOEfLsF1v464dSpy1tQVHhhp8LFTxh/6RWkRIR2uF I4v3Xu/k5D0LhaZHpQ4C+xKsQxpTGuYh2tnRaRL14YMW1dlI3HfeB2gj7Yc8XdHh9vkpPyuT nY/ZsFbnvBtiw7GchKKri2gDhRb2QNNDyBnQn5mRFw7CyuFclAksOdV/sdpQnYlYcRQWOUGY HhQ5eqTRZjm9z+qQe/T0HQpmiPTqQcIaG/edgKVTUjITfA7AJMKLQHgp04Vylb+G6jocnQQX JqvvP09whbqrABEBAAHCwWUEGAECAA8CGwwFAlVcpi8FCRmg08MACgkQyx8mb86fmYHNRQ/+ J0OZsBYP4leJvQF8lx9zif+v4ZY/6C9tTcUv/KNAE5leyrD4IKbnV4PnbrVhjq861it/zRQW cFpWQszZyWRwNPWUUz7ejmm9lAwPbr8xWT4qMSA43VKQ7ZCeTQJ4TC8kjqtcbw41SjkjrcTG wF52zFO4bOWyovVAPncvV9eGA/vtnd3xEZXQiSt91kBSqK28yjxAqK/c3G6i7IX2rg6pzgqh hiH3/1qM2M/LSuqAv0Rwrt/k+pZXE+B4Ud42hwmMr0TfhNxG+X7YKvjKC+SjPjqp0CaztQ0H nsDLSLElVROxCd9m8CAUuHplgmR3seYCOrT4jriMFBtKNPtj2EE4DNV4s7k0Zy+6iRQ8G8ng QjsSqYJx8iAR8JRB7Gm2rQOMv8lSRdjva++GT0VLXtHULdlzg8VjDnFZ3lfz5PWEOeIMk7Rj trjv82EZtrhLuLjHRCaG50OOm0hwPSk1J64R8O3HjSLdertmw7eyAYOo4RuWJguYMg5DRnBk WkRwrSuCn7UG+qVWZeKEsFKFOkynOs3pVbcbq1pxbhk3TRWCGRU5JolI4ohy/7JV1TVbjiDI HP/aVnm6NC8of26P40Pg8EdAhajZnHHjA7FrJXsy3cyIGqvg9os4rNkUWmrCfLLsZDHD8FnU mDW4+i+XlNFUPUYMrIKi9joBhu18ssf5i5Q= Message-ID: <6cb6b5f2-52a3-c7c3-9a10-7dd0f86414a8@roeck-us.net> Date: Mon, 8 Mar 2021 21:24:59 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org On 3/8/21 8:36 PM, Chris Packham wrote: > > On 9/03/21 11:10 am, Chris Packham wrote: >> >> On 8/03/21 5:59 pm, Guenter Roeck wrote: >>> On 3/7/21 8:37 PM, Chris Packham wrote: >>> [ ... ] >>>>> That's from -ENXIO which is used in only one place in i2c-mpc.c. I'll >>>>> enable some debug and see what we get. >>>> For the errant readings there was nothing abnormal reported by the >>>> driver. >>>> >>>> For the "No such device or address" I saw "mpc-i2c ffe119000.i2c: No >>>> RXAK" which matches up with the -ENXIO return. >>>> >>> Id suggest to check the time until not busy and stop in mpc_xfer(). >>> Those hot loops are unusual, and may well mess up the code especially >>> if preempt is enabled. >> Reworking those loops seems to have had a positive result. I'll do a >> bit more testing and hopefully get a patch out later today. > D'oh my "fix" was to replace the cond_reshed() with msleep(10) which did > "fix" the problem but made every i2c read slow. I didn't notice when > testing just the lm81 but as soon as I booted the system with more i2c > devices I saw stupidly slow boot times. msleep() is indeed a bad idea. You'd want something like usleep_range() with increasing timeout. Like start with a few uS and double the sleep time with each iteration (eg 4-8 / 8-16 / 16-32 / 32-64 / ...). Guenter