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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B764C433EF for ; Mon, 27 Sep 2021 08:19:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ED344604DB for ; Mon, 27 Sep 2021 08:19:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233382AbhI0IVA convert rfc822-to-8bit (ORCPT ); Mon, 27 Sep 2021 04:21:00 -0400 Received: from relay9-d.mail.gandi.net ([217.70.183.199]:52465 "EHLO relay9-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233337AbhI0IVA (ORCPT ); Mon, 27 Sep 2021 04:21:00 -0400 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay9-d.mail.gandi.net (Postfix) with ESMTPSA id C4D80FF805; Mon, 27 Sep 2021 08:19:07 +0000 (UTC) Date: Mon, 27 Sep 2021 10:18:54 +0200 From: Miquel Raynal To: Lee Jones Cc: Jonathan Cameron , Lars-Peter Clausen , Peter Meerwald-Stadler , Rob Herring , Dmitry Torokhov , bcousson@baylibre.com, Tony Lindgren , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-omap@vger.kernel.org, Thomas Petazzoni , Vignesh Raghavendra , Lokesh Vutla , Tero Kristo , Ryan Barnett , Grygorii Strashko , Jason Reeder , Jonathan Cameron Subject: Re: [PATCH v3 36/47] mfd: ti_am335x_tscadc: Support the correctly spelled DT property Message-ID: <20210927101854.5df3ac6f@xps13> In-Reply-To: References: <20210915155908.476767-1-miquel.raynal@bootlin.com> <20210915155908.476767-37-miquel.raynal@bootlin.com> <20210923101922.2c108d2b@xps13> <20210923113312.14fc9027@xps13> Organization: Bootlin X-Mailer: Claws Mail 3.17.7 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Hi Lee, lee.jones@linaro.org wrote on Mon, 27 Sep 2021 09:09:32 +0100: > On Thu, 23 Sep 2021, Miquel Raynal wrote: > > > Hi Lee, > > > > lee.jones@linaro.org wrote on Thu, 23 Sep 2021 10:11:13 +0100: > > > > > On Thu, 23 Sep 2021, Miquel Raynal wrote: > > > > > > > Hi Lee, > > > > > > > > lee.jones@linaro.org wrote on Wed, 22 Sep 2021 16:57:10 +0100: > > > > > > > > > On Wed, 15 Sep 2021, Miquel Raynal wrote: > > > > > > > > > > > There was in the past a typo in the coordinate readouts property. The > > > > > > bindings have been updated, the touchscreen driver as well and now > > > > > > supports both. However, the MFD driver that is in charge of verifying > > > > > > the validity of the property only checks the bogus one. Add support for > > > > > > the correctly spelled DT property. > > > > > > > > > > > > Fixes: c9aeb249bf72 ("Input: ti_am335x_tsc - fix spelling mistake in TSC/ADC DT binding") > > > > > > Signed-off-by: Miquel Raynal > > > > > > Reviewed-by: Jonathan Cameron > > > > > > --- > > > > > > drivers/mfd/ti_am335x_tscadc.c | 8 +++++++- > > > > > > 1 file changed, 7 insertions(+), 1 deletion(-) > > > > > > > > > > > > diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c > > > > > > index 155a8ed879b3..aa46ed669016 100644 > > > > > > --- a/drivers/mfd/ti_am335x_tscadc.c > > > > > > +++ b/drivers/mfd/ti_am335x_tscadc.c > > > > > > @@ -144,8 +144,14 @@ static int ti_tscadc_probe(struct platform_device *pdev) > > > > > > if (tscadc->data->has_tsc) { > > > > > > node = of_get_child_by_name(pdev->dev.of_node, "tsc"); > > > > > > of_property_read_u32(node, "ti,wires", &tscmag_wires); > > > > > > - of_property_read_u32(node, "ti,coordiante-readouts", &readouts); > > > > > > + err = of_property_read_u32(node, "ti,coordinate-readouts", > > > > > > + &readouts); > > > > > > + if (err < 0) > > > > > > + of_property_read_u32(node, "ti,coordiante-readouts", > > > > > > + &readouts); > > > > > > + > > > > > > > > > > How long are you proposing that we support this churn? > > > > > > > > Well, I am not proposing anything, I am just "fixing" the driver so > > > > that it fits the bindings :) Given the fact that at the end of this > > > > series there is a patch that changes the "coordiante" typo to > > > > "coordinate" in a device tree source file, I believe it is still too > > > > soon... > > > > > > If this is something you're changing in this set, please reconsider. > > > > > > I'd rather have a slightly misspelled documented property than being > > > forced to support 2 for any length of time. > > > > I am not suggesting anything here: > > - "coordiante" was introduced back in 2014. > > - "coordinate" was introduced shortly later. > > - "coordiante" was considered part of the "stable API" back in 2014 and > > even though the right spelling got introduced very shortly after, DT > > stability rules wanted us to support it forever. > > - The touchscreen driver has immediately be fixed to support both but > > not the MFD driver, and this does not make any sense! > > > > We *should* either support only one property (1) or support both in the > > two drivers (2), but supporting the two in one driver and supporting > > only one in the other one does not make any sense (given the fact that > > these two drives are tied together, the touchscreen driver does not > > exist without the MFD driver). That is what I am fixing here. > > > > Is #1 valid? Theoretically it's the best scenario. In practice it is > > not (yet) possible because the two versions are still used in the > > mainline device trees: > > $ git grep coordiante-readouts -- arch/arm/boot/dts/ | wc -l > > 1 > > $ git grep coordinate-readouts -- arch/arm/boot/dts/ | wc -l > > 5 > > > > So in this series I am fixing the MFD driver to be sure it handles > > correctly the correctly spelled DT property which is used by 5 boards > > since at least 6 years and I am also updating the remaining DT to use > > the correctly spelled property as well. > > > > I suppose we could propose to drop support for the "coordiante" > > version of that property in a few years but if we decide to do it right > > now we're definitely gonna break users. > > It's a shame that the misspelled one is still in use. If they were > all changed over at the start, there would be a strong case for > dropping support for it. It is, clearly. I believe all DT got changed in one go, but a contributor at the same time proposed a new DT with the legacy property "copy-pasted" from the "existing" device trees and this went off the radar... Anyway, I'll send a v4 soon with all your suggestions taken into account. Thanks, Miquèl