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 C0813C77B7A for ; Wed, 17 May 2023 09:10:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230190AbjEQJKR (ORCPT ); Wed, 17 May 2023 05:10:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55800 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230468AbjEQJKK (ORCPT ); Wed, 17 May 2023 05:10:10 -0400 Received: from mail-pf1-x42b.google.com (mail-pf1-x42b.google.com [IPv6:2607:f8b0:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7270B3C30; Wed, 17 May 2023 02:10:09 -0700 (PDT) Received: by mail-pf1-x42b.google.com with SMTP id d2e1a72fcca58-64a9335a8e7so11684194b3a.0; Wed, 17 May 2023 02:10:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1684314609; x=1686906609; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=lQVT9+5iZHDvM+4sOdIDONXV8SnNYUsj9FcqBhfBcQM=; b=Ye/P+cS2GAnNadzY9LXw7I08PBeU8OnA8LX2MToAi+8E42GvOH9SkWX0pni5H7unOo XVNWhkT21bNL690o5tJVj2GJOvlhJo0JTUzs+Ci49JkwwVJY803BdYpghfKWF+313gHQ 2/JIHXYIaJvzOTSRV4ImRH1IrUx3UHqgjyS3iYo/hpvEYcnmKKRiLjEMEoG/T6wfzY7F +TS9WbfiXhZ3fX059qQqWnCm4JmqeEf+nBSJihWuZluROEw2T84X1HxVJKTRmbra2Gvh cj27IbdjZBV97N6tov4Y+9Wv7sX8USxlbLI55hxYOQvGsKWpFW099w7kNRehD7YZWMwr dmfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684314609; x=1686906609; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=lQVT9+5iZHDvM+4sOdIDONXV8SnNYUsj9FcqBhfBcQM=; b=JyhRCgabwH73G9UvWADDj9+I3/Cn0LNX3vNenWveN9FRCt/ft+565om8IEhuTE8Zfs fIQ4HfcgcCavpD6abwvw89TeeQGpxldfpt6Nl2/u6tbEBRFfc61VEwNY3cz7pGQOJ0Gi bFh0m1M2i4twEnWVbqL4BdXmsYrVaLRD4q3t0KDHi9qhoHULvCOFA7xj7P5GjGgA3ISU TssHHGGsCkpqPmYfNVlr5veKiI+xn3Ui72siXzrCTo6aiISPfwXa6ICT2HEoVh9qsh2l yp6+ZT9oKP6+lT/V6SswgOsM2qfM9JPrLH6ICVzLMqNDbYgJF4QPmPlylYeOZu3vNae5 qmTw== X-Gm-Message-State: AC+VfDzB12Zxtx3aH7Y9pozti5VpK71lhwXZqv2FacE+EzTOF2Vnf8Vi q+cFDsWfQgRJeiLwWM2SL+8= X-Google-Smtp-Source: ACHHUZ4wb3371ocMUlMVj604rXwLPf+/s0QTiboeqtWQYeFphiwt0hlCI7sFqQCGTRE5NT0OWfJO/w== X-Received: by 2002:a17:90a:ee4a:b0:250:69de:7157 with SMTP id bu10-20020a17090aee4a00b0025069de7157mr1990983pjb.2.1684314608821; Wed, 17 May 2023 02:10:08 -0700 (PDT) Received: from sol (194-223-178-180.tpgi.com.au. [194.223.178.180]) by smtp.gmail.com with ESMTPSA id r5-20020a17090aad0500b00247150f2091sm1070766pjq.8.2023.05.17.02.10.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 May 2023 02:10:08 -0700 (PDT) Date: Wed, 17 May 2023 17:10:02 +0800 From: Kent Gibson To: Andy Shevchenko Cc: Chris Packham , Linus Walleij , "brgl@bgdev.pl" , "johan@kernel.org" , "maz@kernel.org" , Ben Brown , "linux-gpio@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] gpiolib: Avoid side effects in gpio_is_visible() Message-ID: References: <20230512042806.3438373-1-chris.packham@alliedtelesis.co.nz> <31a23398-9b0e-4a19-3576-84fcfd3ce4b5@alliedtelesis.co.nz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On Wed, May 17, 2023 at 11:54:58AM +0300, Andy Shevchenko wrote: > On Wed, May 17, 2023 at 2:50 AM Chris Packham > wrote: > > On 17/05/23 10:47, Kent Gibson wrote: > > ... > > > I'm sure both of these applications could be re-written around libgpiod > > but that would incur a significant amount of regression testing on > > existing platforms. And I still consider dealing with GPIO chips an > > extra headache that the applications don't need (particularly with the > > sheer number of them the SFP case). > > It seems to me that having no in-kernel driver for your stuff is the > main point of all headache here. But I might be mistaken. > Yeah, that is probably a fair call. I tend to have GPIO blinkers on and try to solve things from userspace, but this application is probably moving outside the bounds that the uAPI (or the much accursed sysfs) is intended for - if you want industrial grade reliability go in-kernel. Cheers, Kent. ps Sorry if I jumped in on this thread uninvited, but with the TZ differences involved I thought it useful.