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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1AD03C433FE for ; Tue, 29 Mar 2022 09:03:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234387AbiC2JEs (ORCPT ); Tue, 29 Mar 2022 05:04:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232241AbiC2JEr (ORCPT ); Tue, 29 Mar 2022 05:04:47 -0400 Received: from mail-wr1-x429.google.com (mail-wr1-x429.google.com [IPv6:2a00:1450:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC304241A12 for ; Tue, 29 Mar 2022 02:03:04 -0700 (PDT) Received: by mail-wr1-x429.google.com with SMTP id j18so23760896wrd.6 for ; Tue, 29 Mar 2022 02:03:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=GcdJM2V/svapdpQ6dIf3sylO9+ETZa0HeWyNvOVMs30=; b=RO87GOqcHbjfCPjs1+UKjDVTt4CaImmkULZ4OPPAgYiRIRdYtkCzFYTz6zm7aGwSL1 mktKT7YS/d3bCnu8Mo7AL9LUUKiEfiRtU12QZDhSfImJO/MTRTct6CdIwuioU3+dBtmb n7cVgX04VboKxTYEQRx5JZFtBOHxVbrZQWPCn5KaoIaDhXTOLq7dCw5zhypw5fLU8x+I UJD+uRCVHqvPqfRDmkHNH4apuQdduvqAYEopt/iEewhp53ubobqD+beQ+JfRZiSjrhfk zD2DogilaPj9Nz+t4piVumaBM/hswd9ItenSr1PtcHcKWetG+vOUt9ycLNQSCfMSl9Pg Dfbw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=GcdJM2V/svapdpQ6dIf3sylO9+ETZa0HeWyNvOVMs30=; b=2VR3gOcZMT2Q1ra0lGqB+VJ5uE22Ab0ofkPAxnaWLpfTYBm8uMsVnNL6KMfqvhUz+c LKE8qinPZVTax/31omWzn1mWVGwvgMIKJn6T37ScnrBt3qE3TaYXvN3dROLzCwxA+oha HoFqZqhfcha6Tx1qcEXVwckZRijOwXcMTesWb5SoR9KJQWlMjHPcCvhGuHSMocvNmNRd Kswy4Z899B/TPe+5/pyCBAliRbz6URyrFUVx7z0mFnHhcQDkteAt0HfZh+4XvOdV034R KY8i/kUTXLVB7TcYZjPKUNTt4i5nLkndjhJ4umzi2LzMdqGnYO411OVwlo6rNY1XnmZR FQPg== X-Gm-Message-State: AOAM530zyziGLgA4dR9exIFbUNdAqrBh/JWdOgiIDDyUSF/DBNM+tmle tMvy3cEJRb/pG17V9xMPmbU= X-Google-Smtp-Source: ABdhPJyMRrjmlwu9q/7D7Jo39LGfURnTU7UNXKM+8nF8dat9KZBdEmZGnKqotRcipGYTzN4tu9HfOA== X-Received: by 2002:a5d:4245:0:b0:203:dc49:2604 with SMTP id s5-20020a5d4245000000b00203dc492604mr31008343wrr.32.1648544583048; Tue, 29 Mar 2022 02:03:03 -0700 (PDT) Received: from [192.168.1.31] ([90.61.176.186]) by smtp.gmail.com with ESMTPSA id i5-20020adfaac5000000b00203fd04bf86sm14257558wrc.66.2022.03.29.02.03.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 29 Mar 2022 02:03:02 -0700 (PDT) Message-ID: <0fbe9368-ad2c-b3ea-0a2e-f7afbbd278ba@gmail.com> Date: Tue, 29 Mar 2022 11:03:03 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: Edit/gpiomon: Question about mode Content-Language: fr To: Kent Gibson Cc: linux-gpio@vger.kernel.org References: <20220329033840.GA14149@sol> <425f4895-81a9-719a-be74-4c67f9c35b92@gmail.com> <20220329083823.GA94201@sol> <3d6f8156-fcf0-21cf-c9bc-6543d982e89a@gmail.com> <20220329085108.GA114462@sol> From: Hans Kurscheidt In-Reply-To: <20220329085108.GA114462@sol> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Am 29.03.2022 um 10:51 schrieb Kent Gibson: > On Tue, Mar 29, 2022 at 10:43:19AM +0200, Hans Kurscheidt wrote: >> Am 29.03.2022 um 10:38 schrieb Kent Gibson: >>> On Tue, Mar 29, 2022 at 10:07:57AM +0200, Hans Kurscheidt wrote: >>>> Am 29.03.2022 um 05:38 schrieb Kent Gibson: >>>>> On Mon, Mar 28, 2022 at 07:13:13PM +0200, Hans Kurscheidt wrote: >>>>>> Am 28.03.2022 um 15:16 schrieb Hans Kurscheidt: >>>>>>> Hi, >>>>>>> >>>>>>> what would be the right mode for gpiomon call from >>>>>>> >>>>>>> a shellscript executed as root from systemd at system start >>>>>>> >>>>>>> waiting on a Pin w/ pullup for invoking shutdown upon rising* edge. >>>>>>> *changed >>>>>>> >>>>>>> >>>>>>> Lots of interupts, Signals and other GPIO ongoing from other user APPs & >>>>>>> threads in multi-user state. >>>>>> 2b more precise: I wired a GPIO Pin to GND. >>>>>> >>>>>> Upon the cmd: sudo gpiomon -r -n1 >>>>>> >>>>>> the program exits immediately with 1 event, although there was never a >>>>>> rising edge due to the fix wire to GND. Is this a feature or a bug, and is >>>>>> it reproducible? >>>>>> >>>>> Not a feature and not reproducible for me on a Raspberry Pi4 with the >>>>> setup you describe, so probably a bug specific to your hardware platform, >>>>> whatever that may be. >>>>> >>>>> If it is 100% reproduceable for you, and assuming it is an initialisation >>>>> issue so you only get the one spurious event, how about using -n2 as a >>>>> workaround ;-)? >>>>> >>>>> Cheers, >>>>> Kent. >>>> It appears 2b reproduceable 100% on my OrangePi zero+ (Allwinner H5) and >>>> using -n2 does the trick, but isn't gpiod not supposed to work on all >>>> commercial HW platforms and related kernels, rather then only on RPI?? >>>> >>> gpiod will work on any platform with a supporting kernel. >>> How well depends on the underlying hardware and driver. >>> The RPi4 was merely a counter-example demonstrating that your issue is >>> not universal, using hardware I happen to have readily available. >>> >>> Cheers, >>> Kent. >> So if I understand you right, gpiod works on sort of a logical level, while >> the HW dependend part depends of the kernel driver implementation of the >> specific HW? >> >> > libgpiod is a userspace library and tools to access GPIO lines via the > Linux GPIO character device. The actual interfacing to the hardware is > performed by the kernel and appropriate drivers for your hardware. > As your problem does not exhibit on other hardware, the root cause > of your problem probably lies in the driver for your hardware, not in > libgpiod nor the gpiolib subsystem of the kernel. > > But you would need to debug it further to be sure. > > Cheers, > Kent. OK, thank's. I'll raise a bug report for the OPI kernel guys in the ARMBIAN forum.