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 854C4C433FE for ; Fri, 20 May 2022 09:12:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236016AbiETJMP (ORCPT ); Fri, 20 May 2022 05:12:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58930 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235950AbiETJMO (ORCPT ); Fri, 20 May 2022 05:12:14 -0400 Received: from wp530.webpack.hosteurope.de (wp530.webpack.hosteurope.de [IPv6:2a01:488:42:1000:50ed:8234::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 57CD15C350; Fri, 20 May 2022 02:12:11 -0700 (PDT) Received: from [2a02:8108:963f:de38:eca4:7d19:f9a2:22c5]; authenticated by wp530.webpack.hosteurope.de running ExIM with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) id 1nryg4-0005aV-3Z; Fri, 20 May 2022 11:12:08 +0200 Message-ID: Date: Fri, 20 May 2022 11:12:06 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Content-Language: en-US To: Bartosz Golaszewski , Linus Walleij Cc: Marcelo Roberto Jimenez , stable , regressions@lists.linux.dev, "open list:GPIO SUBSYSTEM" , Thierry Reding , Vidya Sagar , Geert Uytterhoeven , Stephen Rothwell , Edmond Chung , Andrew Chant , Will McVicker , Sergio Tanzilli References: <20211217153555.9413-1-marcelo.jimenez@gmail.com> From: Thorsten Leemhuis Subject: Re: [PATCH] gpio: Revert regression in sysfs-gpio (gpiolib.c) In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-bounce-key: webpack.hosteurope.de;regressions@leemhuis.info;1653037931;c259e5ef; X-HE-SMSGID: 1nryg4-0005aV-3Z Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On 16.02.22 15:40, Bartosz Golaszewski wrote: > On Tue, Feb 15, 2022 at 10:56 PM Linus Walleij wrote: >> >> On Mon, Feb 14, 2022 at 12:24 AM Marcelo Roberto Jimenez >> wrote: >>> On Sat, Feb 12, 2022 at 1:55 PM Linus Walleij wrote: >> >>>> I am curious about the usecases and how deeply you have built >>>> yourselves into this. >>> >>> I don't know if I understand what you mean, sorry. >> >> Why does the user need the sysfs ABI? What is it used for? >> >> I.e what is the actual use case? >> >>>>> In any case, the upstream file should be enough to test the issue reported here. >>>> >>>> The thing is that upstream isn't super happy that you have been >>>> making yourselves dependent on features that we are actively >>>> discouraging and then demanding that we support these features. >>> >>> Hum, demanding seems to be a strong word for what I am doing here. >>> >>> Deprecated should not mean broken. My point is: the API seems to be >>> currently broken. User space apps got broken, that's a fact. I even >>> took the time to bisect the kernel and show you which commit broke it. >>> So, no, I am not demanding. More like reporting and providing a >>> temporary solution to those with a similar problem. >>> >>> Maybe it is time to remove the API, but this is up to "upstream". >>> Leaving the API broken seems pointless and unproductive. >>> >>> Sorry for the "not super happiness of upstream", but maybe upstream >>> got me wrong. >>> >>> We are not "making ourselves dependent on features ...". The API was >>> there. We used it. Now it is deprecated, ok, we should move on. I got >>> the message. >> >> Ouch I deserved some slamming for this. >> >> I'm sorry if I came across as harsh :( >> >> I just don't know how to properly push for this. >> >> I have even pushed the option of the deprecated sysfs ABI >> behind the CONFIG_EXPERT option, which should mean that >> the kernel config has been made by someone who has checked >> the option "yes I am an expert I know what I am doing" >> yet failed to observe that this ABI is obsoleted since 5 years >> and hence failed to be an expert. >> >> Of course the ABI (not API really) needs to be fixed if we can find the >> problem. It's frustrating that fixing it seems to fix broken other >> features which are not deprecated, hence the annoyance on my >> part. >> > > I'm afraid we'll earn ourselves a good old LinusRant if we keep > pushing the character device as a solution to the problem here. > Marcelo is right after all: he used an existing user interface, the > interface broke, it must be fixed. > > I would prefer to find a solution that fixes Marcelo's issue while > keeping the offending patches in tree but it seems like the issue is > more complicated and will require some rework of the sysfs interface. > > In which case unless there are objections I lean towards reverting the > relevant commits. Reviving and old thread, hence a quick reminder: The patch at the start of this thread was applied and then reverted in 56e337f2cf13 with this text: ``` This commit - while attempting to fix a regression - has caused a number of other problems. As the fallout from it is more significant than the initial problem itself, revert it for now before we find a correct solution. ``` I still have this on my list of open regressions and that made me wonder: is anyone working on a "correct solution" (or was one even applied and I missed it)? Or is the situation so tricky that we better leave everything as it is? Marcelo, do you still care? Ciao, Thorsten