From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f173.google.com (mail-pf1-f173.google.com [209.85.210.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C08911DF759 for ; Sun, 1 Feb 2026 01:25:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769909104; cv=none; b=NOXlVjJdenX8cyMmA8I5mJ7Ju4+FcmkGa+sr4x0q7n9CpLz5D5zLpHFJYE3VlO/nkgaTJ7HVFJD/7pR6bLn2ZB6kYNvYS0d3hXW0S1kNAc0WkWv56YO4MM+MAhsXFE7NZKm8EXo+12rPyK44SFvKvxo37q7lHknIfNfoQnrPXXw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769909104; c=relaxed/simple; bh=1zJieALU8h1RXKP7jBg8CVRQ4QNRYUzTmQe61tr82mM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tgN4b7B9k7k2Z3zEn6VdCBHB4KB80JfpJBq0+/lnzLzNGTJStkSVylE/6QcPHrBKcGWFmQgYruxi1zqpiWQF1dFVquMN9IyQ9dIRH3XYtTfHoSTlsF4uIMvs1pZwH8Gz+6YUOHNUf1LMD0TDQg239LdasAgZrA/7j/Tz007QSWc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=roeck-us.net; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=SXklu7VO; arc=none smtp.client-ip=209.85.210.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=roeck-us.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SXklu7VO" Received: by mail-pf1-f173.google.com with SMTP id d2e1a72fcca58-8220bd582ddso1876399b3a.2 for ; Sat, 31 Jan 2026 17:25:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1769909102; x=1770513902; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:sender:from:to:cc:subject:date:message-id:reply-to; bh=CvLvljMAsvteMqSz8F1hEW5JiUfBr6cONobzhspFMuI=; b=SXklu7VOopOZHhZYU7zqjmECgEDW6jyBAtONaZWj9UoXh8ot48QubOMx2fZC7iIoQd 8CcUB2XndfyjQ6+GMpO4ldWmUOx5v+B9y+g+gMfkCaqV7Uqu/qo8qchOFUhuRP4sGFz2 qMAX/tyvb8Z4QFJKw1ctGRHVugN+Nxp7LDGb1NwIGQwSZwdc4j1pLlo25Xf1Ah3sykzr M64acQdPj3gB1qhCwjMHTCXHLX6iaH6qhTXgiis2o/06fCNStrl/FLcj9xp0vhrM4Sf7 DG8Jd+8Is9yeDtdT+h+tEGPkHyIzuTv6l02MfNZqj0CSLdibqw3/2ug9cIa2oINguHIE okyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769909102; x=1770513902; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:sender:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=CvLvljMAsvteMqSz8F1hEW5JiUfBr6cONobzhspFMuI=; b=ou5jDllY0vEBVd1+120iLwWpYEJr5KgGj4MLao167rAeF7BHESiATovCVnwMQCe2LF WJzt5msByH80mNFNmzyrKTC2M4catZVsFdXXTzone63gidbFRStkKsa/hiemaeo6z52s zAJ770BUAD8PNSfDIUPRJDnu2sKVAJCCR+0ZbG+GZG/1HvKb1lPOco5+XwgzAaSQLJtV 4Q/haPNtNwj7RKeW8CVrGaCIdlYHFAA3OCFYUDNJlA+jUQT8iATwM/agvNYfvwuIdCnX C0abbj9tCVM0i7QY05Ix3gb3/rgZrPhAqqo2SWwIskv0qk8SKlzQWxH3AD/Nho5Q5xyI ykbQ== X-Forwarded-Encrypted: i=1; AJvYcCWZ8zjI5JmLpjPGLswOG3lkzt78dMQtJqF04uO1Rr/pNGOs3Zijo5298W2lDroIk2XUn+l2BUa8ElxyZSY=@vger.kernel.org X-Gm-Message-State: AOJu0YxbyBppH3jMs9Ukw649HO2DoS5fkqt141FXADG8uf39EtF5z+u6 i/wGUF/l7o8cdTnb9oCYI6VzcSN35l8mjA/54xf8eObj/A2qh+4Tbl77 X-Gm-Gg: AZuq6aI0c1PcnpyY6pFyXFG40+yTcVcxURud8pXNfFUC0OKNmA8/2GNH83XV+mKZ2qo GtGzFTSMPz3cI1B3Ikc3Dgfklr6cFjxa5n9ME4Hu/94iQKtEYaJvs80zkcLsLMzvFq8T8ERSaCM aBsPdoJJejA6OTchoEnQfCia9RzaP6BbTdp9a86GA73uPr/CK7X8uho8s8Loo9eaUiGjpqGVXKH kkkz1jwtM+F/w6oFvK8UCl12l0w5+fFNSTX79SgFhFbv96er4a04+oZK9szjipjDk6nQkxhIL1W cTxcy/iJjn3MGi2pS9JKiGgsaxXakRCgI+QPlkH2qIG1cfAXVehViVTmXxJPUFqKPaPOXDo5Vc1 2LJqc7GcPD8T3i84zgvuSi/6Uyx+HgnyEwBPTwbuy5mD+gOW+c4W9C236T8IfLoe8bXc6BLvGff Vqn0XXEVd3ZlTCoRQ+M0oqUBwMpJZfm9De20x6vcjwO43YXpgMp646Gg4UDFhe X-Received: by 2002:a05:6a20:1605:b0:38b:ea2a:2843 with SMTP id adf61e73a8af0-392dffe90fcmr7782753637.10.1769909102009; Sat, 31 Jan 2026 17:25:02 -0800 (PST) Received: from ?IPV6:2600:1700:e321:62f0:da43:aeff:fecc:bfd5? ([2600:1700:e321:62f0:da43:aeff:fecc:bfd5]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-c642a9f49fasm10612078a12.28.2026.01.31.17.25.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 31 Jan 2026 17:25:01 -0800 (PST) Sender: Guenter Roeck Message-ID: Date: Sat, 31 Jan 2026 17:25:00 -0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/3] hwmon: spd5118: Do not fail resume on temporary I2C errors To: TINSAE TADESSE Cc: Armin Wolf , "linux-hwmon@vger.kernel.org" , linux-kernel@vger.kernel.org References: <20260110172003.13969-1-tinsaetadesse2015@gmail.com> <2740c3ab-7cb0-4931-81a2-30b85e8615f9@roeck-us.net> <39b48803-e236-4acc-84e9-18162770f9ae@roeck-us.net> <5ecc96da-0c87-45f6-ab57-c3ea8eb28de1@gmx.de> Content-Language: en-US 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 CQgHAwIGFQgCCQoLBBYCAwECHgECF4ACGQEFAmgrMyQFCSbODQkACgkQyx8mb86fmYGcWRAA oRwrk7V8fULqnGGpBIjp7pvR187Yzx+lhMGUHuM5H56TFEqeVwCMLWB2x1YRolYbY4MEFlQg VUFcfeW0OknSr1s6wtrtQm0gdkolM8OcCL9ptTHOg1mmXa4YpW8QJiL0AVtbpE9BroeWGl9v 2TGILPm9mVp+GmMQgkNeCS7Jonq5f5pDUGumAMguWzMFEg+Imt9wr2YA7aGen7KPSqJeQPpj onPKhu7O/KJKkuC50ylxizHzmGx+IUSmOZxN950pZUFvVZH9CwhAAl+NYUtcF5ry/uSYG2U7 DCvpzqOryJRemKN63qt1bjF6cltsXwxjKOw6CvdjJYA3n6xCWLuJ6yk6CAy1Ukh545NhgBAs rGGVkl6TUBi0ixL3EF3RWLa9IMDcHN32r7OBhw6vbul8HqyTFZWY2ksTvlTl+qG3zV6AJuzT WdXmbcKN+TdhO5XlxVlbZoCm7ViBj1+PvIFQZCnLAhqSd/DJlhaq8fFXx1dCUPgQDcD+wo65 qulV/NijfU8bzFfEPgYP/3LP+BSAyFs33y/mdP8kbMxSCjnLEhimQMrSSo/To1Gxp5C97fw5 3m1CaMILGKCmfI1B8iA8zd8ib7t1Rg0qCwcAnvsM36SkrID32GfFbv873bNskJCHAISK3Xkz qo7IYZmjk/IJGbsiGzxUhvicwkgKE9r7a1rOwU0ETofVZwEQALlLbQeBDTDbwQYrj0gbx3bq 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 JqvvP09whbqrABEBAAHCwWUEGAECAA8CGwwFAmgrMyQFCSbODQkACgkQyx8mb86fmYHlgg/9 H5JeDmB4jsreE9Bn621wZk7NMzxy9STxiVKSh8Mq4pb+IDu1RU2iLyetCY1TiJlcxnE362kj njrfAdqyPteHM+LU59NtEbGwrfcXdQoh4XdMuPA5ADetPLma3YiRa3VsVkLwpnR7ilgwQw6u dycEaOxQ7LUXCs0JaGVVP25Z2hMkHBwx6BlW6EZLNgzGI2rswSZ7SKcsBd1IRHVf0miwIFYy j/UEfAFNW+tbtKPNn3xZTLs3quQN7GdYLh+J0XxITpBZaFOpwEKV+VS36pSLnNl0T5wm0E/y scPJ0OVY7ly5Vm1nnoH4licaU5Y1nSkFR/j2douI5P7Cj687WuNMC6CcFd6j72kRfxklOqXw zvy+2NEcXyziiLXp84130yxAKXfluax9sZhhrhKT6VrD45S6N3HxJpXQ/RY/EX35neH2/F7B RgSloce2+zWfpELyS1qRkCUTt1tlGV2p+y2BPfXzrHn2vxvbhEn1QpQ6t+85FKN8YEhJEygJ F0WaMvQMNrk9UAUziVcUkLU52NS9SXqpVg8vgrO0JKx97IXFPcNh0DWsSj/0Y8HO/RDkGXYn FDMj7fZSPKyPQPmEHg+W/KzxSSfdgWIHF2QaQ0b2q1wOSec4Rti52ohmNSY+KNIW/zODhugJ np3900V20aS7eD9K8GTU0TGC1pyz6IVJwIE= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 1/31/26 11:50, TINSAE TADESSE wrote: ... > > Hi Guenter, > > While investigating this issue, I previously mentioned > about a flow where SPD write disabled state can be > exported as a capability from the i801 controller, so > that the SPD5118 hwmon driver consumes it. > > The SPD write disabled state is known to the controller > driver (i2c-i801), but this information is not > propagated to client drivers. As a result, auto-detected > devices may be instantiated and probed even though the > controller cannot support the required access model. > > This raises a major architectural question: > > Should SMBus / I2C controller drivers be able to > advertise bus-level capability constraints (such as SPD > write disabled state) to client drivers, so that clients can > make an informed decision during probe? > > A capability-based approach would allow: > * controller drivers to expose what is possible on a given bus > * client drivers to decide whether they can operate correctly > * avoidance of device-specific policy in controller drivers > * consistent handling across different SPD-capable devices > > I actually tested the possibility of detecting, propagating, > and consuming the SPD write disabled state using an I2C > adapter capability flag. Using this approach, I was able to > fix the issue even with the CONFIG_SENSORS_SPD5118_DETECT > kernel configuration enabled. > > At this stage, I am not proposing a specific implementation. > The goal of this RFC is to get agreement on whether this type > of problem should be solved through capability propagation, > and if so, what mechanism would be preferred. > > Any feedback on design direction, or existing infrastructure > that could be reused would be very welcome. > I think it is a good idea, but how would the flag look like ? The i801 controller only write protects a range of addresses; I think it is 0x50..0x57. So any I2C_FUNC flag would presumably have to be address range specific. You could try adding something like I2C_FUNC_SPD_WRITE_PROTECTED. Either case, you'll have to ask the I2C subsystem maintainers for advice. I would suggest to give it a try. Thanks, Guenter