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 369C1C41513 for ; Thu, 3 Aug 2023 21:39:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231496AbjHCVjH (ORCPT ); Thu, 3 Aug 2023 17:39:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44268 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231129AbjHCVjG (ORCPT ); Thu, 3 Aug 2023 17:39:06 -0400 Received: from mail.hugovil.com (mail.hugovil.com [162.243.120.170]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5CE1730F6; Thu, 3 Aug 2023 14:39:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=hugovil.com ; s=x; h=Subject:Content-Transfer-Encoding:Content-Type:Mime-Version: References:In-Reply-To:Message-Id:Cc:To:From:Date:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=+c3D1I04CXR8c7DhRfh0Z01N29Lf7zWiuh+iDe/1XJI=; b=iOHf37hTskOO8FjsCPPCe2JIXK /vm9ZCMWUKO/eqztrPGsPmN7zpLnfMkojpNL2kck7KCFf5BPXBMZEQ4dX1Gqz9wztCAC0DjmFU0ll 7g+Lw5MN6tb2VKiDyVka8bentCG6yPIan1rtvz+iaEO1f73b8I/9Irrgy7Ueb8YncygQ=; Received: from modemcable061.19-161-184.mc.videotron.ca ([184.161.19.61]:45150 helo=pettiford) by mail.hugovil.com with esmtpa (Exim 4.92) (envelope-from ) id 1qRg23-0005Hc-NM; Thu, 03 Aug 2023 17:38:56 -0400 Date: Thu, 3 Aug 2023 17:38:54 -0400 From: Hugo Villeneuve To: Rob Herring Cc: Greg KH , krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, jirislaby@kernel.org, jringle@gridpoint.com, isaac.true@canonical.com, jesse.sung@canonical.com, tomasz.mon@camlingroup.com, l.perczak@camlintechnologies.com, linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, Hugo Villeneuve , stable@vger.kernel.org, Andy Shevchenko , Lech Perczak Message-Id: <20230803173854.efdda6d30d88b85ee101ce6b@hugovil.com> In-Reply-To: References: <20230721161840.1393996-1-hugo@hugovil.com> <20230721161840.1393996-7-hugo@hugovil.com> <20230722104724.ef0c5896c239e721794b9fe9@hugovil.com> <2023072240-supremacy-shallot-a77f@gregkh> <20230724115428.d191186852c0bd0ee0d78398@hugovil.com> <20230731124600.39eb8d5c132f9338c2897543@hugovil.com> <20230731144115.14733f0e01f586a7efb91370@hugovil.com> <20230803135401.3a11bfb7c2985c1a90a2521b@hugovil.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 184.161.19.61 X-SA-Exim-Mail-From: hugo@hugovil.com Subject: Re: [RESEND PATCH v8 06/10] serial: sc16is7xx: fix regression with GPIO configuration X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.hugovil.com) Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Thu, 3 Aug 2023 14:10:30 -0600 Rob Herring wrote: > On Thu, Aug 3, 2023 at 11:54 AM Hugo Villeneuve wrote: > > > > On Mon, 31 Jul 2023 14:41:15 -0400 > > Hugo Villeneuve wrote: > > > > > On Mon, 31 Jul 2023 12:04:45 -0600 > > > Rob Herring wrote: > > > > > > > On Mon, Jul 31, 2023 at 10:46 AM Hugo Villeneuve wrote: > > > > > > > > > > On Mon, 31 Jul 2023 09:31:53 -0600 > > > > > Rob Herring wrote: > > > > > > > > > > > On Mon, Jul 24, 2023 at 9:54 AM Hugo Villeneuve wrote: > > > > > > > > > > > > > > On Sat, 22 Jul 2023 17:15:26 +0200 > > > > > > > Greg KH wrote: > > > > > > > > > > > > > > > On Sat, Jul 22, 2023 at 10:47:24AM -0400, Hugo Villeneuve wrote: > > > > > > > > > On Fri, 21 Jul 2023 13:24:19 -0600 > > > > > > > > > Rob Herring wrote: > > > > > > > > > > > > > > > > > > > On Fri, Jul 21, 2023 at 10:19 AM Hugo Villeneuve wrote: > > > > > > > > > > > > > > > > > > > > > > From: Hugo Villeneuve > > > > > > > > > > > > > > > > > > > > > > Commit 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines") > > > > > > > > > > > and commit 21144bab4f11 ("sc16is7xx: Handle modem status lines") > > > > > > > > > > > changed the function of the GPIOs pins to act as modem control > > > > > > > > > > > lines without any possibility of selecting GPIO function. > > > > > > > > > > > > > > > > > > > > Requiring a new DT property is not fixing a kernel regression. You > > > > > > > > > > should be returning the kernel to original behavior and then have a > > > > > > > > > > new DT property for new behavior. > > > > > > > > > > > > > > > > > > Hi Rob, > > > > > > > > > please read the entire patch history starting from V1 > > > > > > > > > and you will understand why this course of action was > > > > > > > > > not selected. > > > > > > > > > > > > > > > > That's not going to happen, sorry, you need to explain it here, in this > > > > > > > > patch series, why a specific action is being taken over another one, as > > > > > > > > no one has time to go dig through past history, sorry. > > > > > > > > > > > > > > Hi Rob, > > > > > > > I initially submitted a patch to revert the kernel to original > > > > > > > behavior, but it created more problems because the patch was > > > > > > > unfortunately split in two separate patches, and mixed with other non > > > > > > > closely-related changes. It was also noted to me that reverting to the > > > > > > > old behavior would break things for some users. > > > > > > > > > > > > > > It was suggested to me by a more experienced kernel developer to > > > > > > > "suggest a fix, instead of hurrying a revert": > > > > > > > > > > > > > > https://lkml.org/lkml/2023/5/17/758 > > > > > > > > > > > > Do I have to go read this to decipher the justification and reasoning? > > > > > > When Greg says "in this patch series", he means in the commit messages > > > > > > of the patches. You send v9 already and it doesn't have that. The > > > > > > patchset needs to stand on its own summarizing any relevant prior > > > > > > discussions. > > > > > > > > > > > > I never suggested doing a revert. > > > > > > > > > > Hi Rob, > > > > > I am sorry, but this is exactly what I "deciphered" from your > > > > > original email. > > > > > > > > > > I am trying very hard to understand exactly what you mean, but it is > > > > > not that obvious for me. If something is not clear in my commit message, > > > > > I will try to improve it. But before, let's try to focus on making sure > > > > > I understand more clearly what you want exactly. > > > > > > > > > > > Obviously, someone still wants the > > > > > > new feature. > > > > > > > > > > I assume that you refer to the "new feature" as what was added in > > > > > the commit 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control > > > > > lines")? > > > > > > > > Shrug. It's one of the 2 commits mentioned, I don't know which one > > > > exactly. Whichever one changed default behavior from use GPIOs to use > > > > modem ctrl lines. > > > > > > > > Reading it again, I *think* this patch is correct. Default behavior is > > > > restored to use GPIOs. The DT property is needed to enable modem ctrl > > > > lines. > > > > > > Hi, > > > this is correct. > > > > > > > > > > What's not okay is just saying, these platforms may or may not need an update: > > > > > > > > arm64/boot/dts/freescale/fsl-ls1012a-frdm.dts > > > > mips/boot/dts/ingenic/cu1830-neo.dts > > > > mips/boot/dts/ingenic/cu1000-neo.dts > > > > > > Yes, my bad. I initially mentioned them and hoped to get some > > > feedback, which I never got, and I kind of forgot about it. > > > > > > > You need to figure that out. Have you checked with maintainers of > > > > these boards? When were they added and by who? At the same time or by > > > > the same person would be a good indication the platform uses modem > > > > ctrl lines. Or were these platforms in use before adding modem ctrl > > > > support? Then they probably use GPIOs or nothing. > > > > > > > > If there are platforms which would regress if the modem ctrl feature > > > > was just reverted, which ones are those? > > > > > > Ok, let me do some checks and get back to you on this. > > > > Hi Rob, > > for this board: > > arm64/boot/dts/freescale/fsl-ls1012a-frdm.dts > > > > it uses a SC16IS740, which doesn't have any GPIOs nor modem > > control lines, so no DT changes required. > > > > For these two Ingenic boards: > > mips/boot/dts/ingenic/cu1830-neo.dts > > mips/boot/dts/ingenic/cu1000-neo.dts > > > > They use a SC16IS752, which has shared modem control lines and GPIOs. > > Unfortunately, the maintainers have not (yet) responded to my > > inquiries. Also, I tried to search for schematics or block diagrams on > > the net but couldn't find anything. > > > > These platforms were in use before the patch to add the modem control > > lines was added. Then like you said they probably use these shared > > lines as GPIOs or nothing, so no DT changes would be required. > > Okay, that's useful (please add to the commit msg). I added the information in the cover letter, but I can add it to the actual patch commit message if you prefer. > Still, what platform(s) need the modem control feature? Presumably > that's whatever platform Lech and Tomasz work on. I guess given the > Reviewed-by they are fine with needing a DT change. Ok. I have previously also emailed Lech about that, but he has not responded yet. Thank you, Hugo.