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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 7374AC2BB48 for ; Wed, 9 Dec 2020 09:26:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DC7423B7B for ; Wed, 9 Dec 2020 09:26:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729210AbgLIJZy (ORCPT ); Wed, 9 Dec 2020 04:25:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45952 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727273AbgLIJZy (ORCPT ); Wed, 9 Dec 2020 04:25:54 -0500 Received: from mail-lj1-x243.google.com (mail-lj1-x243.google.com [IPv6:2a00:1450:4864:20::243]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 789F1C0613D6 for ; Wed, 9 Dec 2020 01:25:13 -0800 (PST) Received: by mail-lj1-x243.google.com with SMTP id a1so1464082ljq.3 for ; Wed, 09 Dec 2020 01:25:13 -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=cYe73lfxXwG2IaSLFmhdyJ4xOtphHHnm36rAnzqmiOo=; b=jt2hDRgS1ZGHz9+htM37Vtc/8gKqxO5FaBCUdCXPTon1+bm4Z1ZBXMFoOIU5mRiIiV cMNqUt9dYhIRLayDICE8ee1srKMkmhM1bbzuQE0cdAJMJd93nMtPpXFVyEuFCRxw5ddy 3PxF0C2ThjnO+2Z5J0w4J422RxHmhjlzZAwKvzdV931t0o9BybZKbapI3i1cia44L5HO rY/jZQwcIP8Xc4S/IomEZdDxcdeOQPQwRC3LeKLquRV/E1YMNj6QwJihhLfhztVST0sp EfrndnjMdlLyTCM/KsLO730oVIpaj/pjMU9coRmjTrizeQOykNM1terH42IA65cMwYsA HVwQ== 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=cYe73lfxXwG2IaSLFmhdyJ4xOtphHHnm36rAnzqmiOo=; b=hZfpUhK6jlr51azoaI/03gH6d3r40Zvo8szsHTqEy2rv/VceBRS6C46Ml48ysTM0Fi XjSKtHDVn4MF53ayBQ4fPE9ZguiW+1Zf7fkVmoe0Ae+YoTjuLtVLaxp2dHUHfsRQxY0/ J5kjLWsecI+AGk7IwNMfkTNeGbsexkObvp8VfOIqWu1QRjXCPL3X94wRmZV7ovZZoCX3 f/tHiVikebXqnCZPFaKzjyqakN+LnQl0MRcG1zS/UlR4UDXMj5BNWl8qv3hKJv5dSUMF GVpTUZbyAiztT2sotsI2aVm2M1sCSBijMPaCsdx3dxRaJVGLrEmLWGmAMt/B9TKecFCX UW+Q== X-Gm-Message-State: AOAM532VJcU9/QCPIRwBEpI+cO/NhMvm+KUr5hquwR4SxNdEy0dlWUDv JoDiFKn51D7NMVQnIEvBCxa5gp01tLuL/1McAHDJDQ== X-Google-Smtp-Source: ABdhPJxyIsnewKjo4ALm9vwM1lKCSFgLErkUx6KRJXVrplD7lgYlsKlPeaqyagO2ZpoaXjHaZ/p5virECuxHrVyx21I= X-Received: by 2002:a05:651c:29c:: with SMTP id b28mr703944ljo.368.1607505911969; Wed, 09 Dec 2020 01:25:11 -0800 (PST) MIME-Version: 1.0 References: <20201204164739.781812-1-maz@kernel.org> <20201204164739.781812-2-maz@kernel.org> In-Reply-To: <20201204164739.781812-2-maz@kernel.org> From: Linus Walleij Date: Wed, 9 Dec 2020 10:25:01 +0100 Message-ID: Subject: Re: [PATCH 1/4] gpiolib: cdev: Flag invalid GPIOs as used To: Marc Zyngier , Bartosz Golaszewski Cc: linux-usb , "open list:GPIO SUBSYSTEM" , "linux-kernel@vger.kernel.org" , Johan Hovold , Greg Kroah-Hartman , kernel-team@android.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Fri, Dec 4, 2020 at 5:47 PM Marc Zyngier wrote: > When reporting the state of a GPIO to userspace, we never check > for the actual validity of the line, meaning we report invalid > lines as being usable. A subsequent request will fail though, > which is an inconsistent behaviour from a userspace perspective. > > Instead, let's check for the validity of the line and report it > as used if it is invalid. This allows a tool such as gpioinfo > to report something sensible: > > gpiochip3 - 4 lines: > line 0: unnamed unused input active-high > line 1: unnamed kernel input active-high [used] > line 2: unnamed kernel input active-high [used] > line 3: unnamed unused input active-high > > In this example, lines 1 and 2 are invalid, and cannot be used by > userspace. > > Signed-off-by: Marc Zyngier This makes sense, so patch applied (unless Bartosz tells me otherwise, then I'll pull it out again). Yours, Linus Walleij