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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 4603DC388F7 for ; Tue, 10 Nov 2020 14:31:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB1F9206D8 for ; Tue, 10 Nov 2020 14:31:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="UFO30gNm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730099AbgKJObg (ORCPT ); Tue, 10 Nov 2020 09:31:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730070AbgKJObg (ORCPT ); Tue, 10 Nov 2020 09:31:36 -0500 Received: from mail-lj1-x241.google.com (mail-lj1-x241.google.com [IPv6:2a00:1450:4864:20::241]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF262C0613CF for ; Tue, 10 Nov 2020 06:31:35 -0800 (PST) Received: by mail-lj1-x241.google.com with SMTP id o24so8230779ljj.6 for ; Tue, 10 Nov 2020 06:31:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=vPuQC/kpZ38anzcR4XBhtMFqVNAip7Kc8QT7E3OTrPM=; b=UFO30gNmb1IuSvSQ/yZ6H6xUZr16EjaijPHT24ZwQIrXgLg8juErJH4dydwjcNccFc zNumqyolrM8+25r2Y7ivqdtyp6wg7xUgnnAqE0tZ0M5I1JRetO5lC2EV5in+KmzDJ0/g 31dmaboN1YpmcAdwMZ6WU8VpiyaXfHRkmHtyCRRlSr5yoC8g7ZH7l6jAMoqEVBYq5hyy fLWM2SvCKpiQIys/3u3RMKogj9IjOuPPtuzy5+hhjvfMCKcQWPcvsBZTjNkBnLj9rhP4 6nFGvaD7mIxj8nLICvIZ55O+XdMdctaup1N3HN+cj3+wpjkUH3NFpYFDYPOgpUHIiZlp 0Qrg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=vPuQC/kpZ38anzcR4XBhtMFqVNAip7Kc8QT7E3OTrPM=; b=HDPP6W3u2aZKBZX38zCWUp+3ooci1hlGQtcf6DKGRp/fJA+xU81egO/lOmapH62u/S wobGVSg0WKbq4tk4ynk5RekRnILhmavJuaAS0Ky7AuDnxbYkaDNqWnLlA1slL7tDupVc o+Q/h7tZ+AVK20j81dZPGc4U331hxpFOHkOH7ata6rvI4c2siwUFs0oAsl/JBGfH4a2W 9xb2Q4HVe3PbstX/i+U19Bi/Ss1o/Lmm5OBnZSnu4UxVb7NO5399ZzTgUedHbBASrDMy f6QqzMKOQyBa/HDqKUxA6n5EjnXgwp1r/PWJsLXFPuvqxqqy4tqAW1vYDuXgMYBZlCT9 Hu9g== X-Gm-Message-State: AOAM531oFCuBVcbt/mUqvbWqmXfUDeMgsrDYoE0KjKOcsOCAaTA3+Aqo 8zwDwMMJ9Z4gbxQF+mjczcAZP6eic89BW6P4Tp/UEpe65dQM+A== X-Google-Smtp-Source: ABdhPJwk7kAYKypJmaeSPrf7+wL4AJ/I5fH6BOhfKS+z5zvrgNNXvLwiyd0ZUMnLUJnTlOfpKHIQGwjiRapQ1//GVJw= X-Received: by 2002:a2e:9a0c:: with SMTP id o12mr7990143lji.104.1605018694483; Tue, 10 Nov 2020 06:31:34 -0800 (PST) MIME-Version: 1.0 References: <20201104115348.51930-1-damien.lemoal@wdc.com> <4dae7924b5d8b020e747a36ecb015063090b819b.camel@wdc.com> In-Reply-To: <4dae7924b5d8b020e747a36ecb015063090b819b.camel@wdc.com> From: Linus Walleij Date: Tue, 10 Nov 2020 15:31:23 +0100 Message-ID: Subject: Re: [PATCH] gpio: Do not trigger WARN() with sysfs gpio export/unexport To: Damien Le Moal Cc: "bgolaszewski@baylibre.com" , "linux-gpio@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On Fri, Nov 6, 2020 at 12:27 PM Damien Le Moal wrote: > It may not be the best interface for regular end users to > manipulate gpios, but it is definitely super useful for developers to do quick > tests of their setup/drivers (which is what I did for my work with the Kendryte > K210 RISC-V SoC support). It is a bit discouraging that RISC-V, which was invented after we already obsoleted the sysfs ABI, is deploying this for development and test. We need to think about a similar facility for users which is less damaging but fulfils the same needs. I think I saw something a while back that looked promising and added some funky files in debugfs in a hierarchical manner per-gpiochip instead. That is how debugfs should be used. Yours, Linus Walleij