From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f47.google.com (mail-pj1-f47.google.com [209.85.216.47]) (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 593BF3A8757 for ; Sat, 11 Apr 2026 15:54:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775922881; cv=none; b=gEKnRkZ8nEMycaTVWMF/LfegsPVkA6pWlzW0bG6D7q+zOdRMjO+N9LrYLzxZVu7Xu+Uzrqn37RjWWUnwZaIqYd0rgoOXoi2Re2c4056dMu6AGf4bPovOTIazu01N5aEnvxj5FSKmi01xvLjDti7La8Hqh7oaIT6dJuKChoIbKYM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775922881; c=relaxed/simple; bh=vyZ3p4QNZDmYaHVFaAa2c29T/arRXgNKIbADpC/E2RY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=geoc6wlhleBXqtwNEFDM8mvuvE0ydLvko2c8VsuS3/KVAhc8tzuUa0UhsK7Vqb/BgIcnzT7tvIUoR0TYxXvnR6iC3hUKTBGSp4ARp3riaVwSTbqVGDjt1QCCVnpJ0QjMzX57RuhP9CHawIdZh0ABYZIZVpESj7jBbUXH60EVjIg= 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=a5FGLWXb; arc=none smtp.client-ip=209.85.216.47 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="a5FGLWXb" Received: by mail-pj1-f47.google.com with SMTP id 98e67ed59e1d1-35d9749c26dso2792142a91.2 for ; Sat, 11 Apr 2026 08:54:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1775922880; x=1776527680; 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=KdjVpbQ+mHdJ8uLjb1LbuXKErsPJPIomY1MUk5b01hY=; b=a5FGLWXbA+ZrxwwsqjwXzqUXV9wVjVCWmKesO6H8aM5/Ka02nkLd0uxVVl2e7QGmoH iQbzHQruqgrqco+l5va1Zhpj3u696v7V1V0+LzmYh4C8RoHrFfOBjBEOm13WndLeFE0K z/JYpUHKEeSfMdf5lbt+6YkRP/irSbE+N0Jb/YgVpRs+PWaQ2Wyi93U7hIaGitLaUBxp nN+IcubwXJjRGXU0dTmwt7jvngppj2wjLIES1oA3dYS4qivOU20p1HmWoJdRS8LxM98+ IxRQNG8H/6x+WlrIbyKEez4A4Oh2kJDu8/Iv8EEKB/P8UVqFUc/Dg1Bh0RfNJrZcvGAc Mzhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775922880; x=1776527680; 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=KdjVpbQ+mHdJ8uLjb1LbuXKErsPJPIomY1MUk5b01hY=; b=XiY/TWMD/n3cfEai4gCdVPij8h/BsFuCjg1NxR7RWJNcF2RVuejj12upAZXAnr3yRY 82erZWFRkKItTJUUG640jLcd/enGy5SloT6SSwO+mlT7cJLM5fTnzWhRbZ9/iaytaCS2 3ZWrY3DXtXwfVxU2WNp8+tDdrCDJgSIhyWhSH1Eo9dY1A4wRb9nL2fsIJIqUcr0fH4IA VSdvBWxZsfKtxYjkoPEVPE7Mh2yoDgYV380PjLM80sbu1IVQdKAy5eW/OKPUXqDSc4qx VXO7PxQdJ7+fmWKjcGNX9UrJEIL/251zi/ewPxgenMPg2OkfRKZ4mtZKmXpGchbzc5VE 6vtg== X-Forwarded-Encrypted: i=1; AFNElJ8OP/6m3z9GrK7m5/qgkaIkQz3rQWPWr+VBLOqsfd3QKOuWbvq91urXz+yi+6c7VUk6+DapRBq/QET/@vger.kernel.org X-Gm-Message-State: AOJu0Yxrk8jYe4zLsVAEoPOavGAffJkP+nAMJqqjli9XvBfpC3EA+SZV W+DweIZyRFbZUjUwGEyeGeD7QqXLTvQUIGKciVZIY2A1iSN47CRjRJVi X-Gm-Gg: AeBDietehAjEPgzj+WjHBVG3sxqA+6xbgEprbeEjQhaAc4Anq1KAxGHHfjnfTVAzI3Q nUTD2Z1KGvwNc/YHdN2eUG3o919P7oCGzmJ4IVDdkLvPCcCfyG99t/qWMMPwvB9vOTloZVEIVgJ 8IdDMQEC/ep2+deJ8AfcWwSiCyRpwBo21BK5QXbjtAcqsAwKI9BRs8SjTtY/FKmMCBku+4Icw76 yXKDUIdErzLp1OYyHStIJqYnFuRMHGwofrLsuHpFYqHzyPiF0H50TlZWRzeUViyB4DonZTN0cT1 PXIoK+7+2KJpR/N0Yw0WqpbUUv03w/dAg6Bs4hYjVNkohiU1aEqxfx9JWBgL5RAUyK2QMrArwv1 97ORz3S+xEfq26Z79ew3QZBL9aweIRPbMImq98XgVzajdixHtZZv1tyH8oxb4BtJhTEPzZy9ZmI qUqG9XS0lX3eerk/gQ6AOOK3pJKuQFSTPaCSj3oZbsw5ulCYNWiQkvJoQexCwLUiVRMzcy//VRO MHIlXPOB6A= X-Received: by 2002:a17:902:9341:b0:2b0:4fb6:85ce with SMTP id d9443c01a7336-2b2d5a45a0bmr58725085ad.21.1775922879656; Sat, 11 Apr 2026 08:54:39 -0700 (PDT) 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 d9443c01a7336-2b2d4f0a39fsm61293595ad.48.2026.04.11.08.54.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 11 Apr 2026 08:54:39 -0700 (PDT) Sender: Guenter Roeck Message-ID: <5b695477-8dc9-49c8-ac0a-51c29604fdbf@roeck-us.net> Date: Sat, 11 Apr 2026 08:54:37 -0700 Precedence: bulk X-Mailing-List: linux-gpio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v9 2/3] hwmon: ltc4283: Add support for the LTC4283 Swap Controller To: =?UTF-8?Q?Nuno_S=C3=A1?= , nuno.sa@analog.com, linux-gpio@vger.kernel.org, linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org, linux-doc@vger.kernel.org Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jonathan Corbet , Linus Walleij , Bartosz Golaszewski References: <20260406-ltc4283-support-v9-0-b66cfc749261@analog.com> <20260406-ltc4283-support-v9-2-b66cfc749261@analog.com> <29b207c8-10ab-42b4-a1c8-988aacc75154@roeck-us.net> <2653dc70f42fd015b88e2744da257f6200603b50.camel@gmail.com> 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: <2653dc70f42fd015b88e2744da257f6200603b50.camel@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 4/11/26 05:38, Nuno Sá wrote: > On Fri, 2026-04-10 at 16:27 -0700, Guenter Roeck wrote: >> On 4/6/26 07:31, Nuno Sá via B4 Relay wrote: >>> From: Nuno Sá >>> >>> Support the LTC4283 Hot Swap Controller. The device features programmable >>> current limit with foldback and independently adjustable inrush current to >>> optimize the MOSFET safe operating area (SOA). The SOA timer limits MOSFET >>> temperature rise for reliable protection against overstresses. >>> >>> An I2C interface and onboard ADC allow monitoring of board current, >>> voltage, power, energy, and fault status. >>> >>> Signed-off-by: Nuno Sá >> >> The patch still has some issues. Please see >> >> https://sashiko.dev/#/patchset/20260406-ltc4283-support-v9-0-b66cfc749261%40analog.com >> >> Specifically: >> >> - regmap_clear_bits() may not cause problems, but it is not the best >>    choice either because the register was already read. >>    It might be better to just write the value to be masked since >>    both the register value and the mask are known. > > Fair enough. > >> >> - I can't comment on the energy accuracy lost. That is your call. >> > > The AI might have a point. Maybe you know better but if I understood correctly, > mul_u64_u64_div_u64() will handle the multiplication by using 128bits (when > available) or if not, using clever tricks. And it should also handle overflows. > > So my feeling is that we can simplify all of those check_overflow paths with the > suggested API. > >> - Clamping before multiplying is indeed wrong. >>    You'll need to clamp before multiplying (and then possibly >>    clamp again). > > Yeah, the clamp change was just nonsense from me. What about about > > val = clamp_val((u64)val * MILLI, ...) > > ? > I don't think that will work on systems where sizeof(long) == 64. I'd suggest to just bite the bullet and clamp against LONG_MAX/MILLI first. > >> -  %*ph: The AI seems to have a point. > > Indeed! > > FWIW, I was already aware of the AI feedback but I'll just setup things locally and > run the review before submitting again. > The AI now copies you on new revisions. Please feel free to rely on that (unless you have tokens to burn, of course ;-). Those AI reviews are cheap for what they do, but they are expensive in absolute terms. Thanks, Guenter