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 C45BCC433FE for ; Sun, 23 Oct 2022 12:39:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230113AbiJWMjl (ORCPT ); Sun, 23 Oct 2022 08:39:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230108AbiJWMjk (ORCPT ); Sun, 23 Oct 2022 08:39:40 -0400 Received: from mail-qt1-x834.google.com (mail-qt1-x834.google.com [IPv6:2607:f8b0:4864:20::834]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 513531AF2A for ; Sun, 23 Oct 2022 05:39:37 -0700 (PDT) Received: by mail-qt1-x834.google.com with SMTP id s3so4301871qtn.12 for ; Sun, 23 Oct 2022 05:39:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=WtMX72KLBH/oqLRTjw6ZoQ9HphAQ86EWlsGtUM1biLY=; b=rR/rt3NVFszMvYLvpbh47uWTrABK35J57rG52zoILjoYOQHkbtYIQh00iQYClie0y3 sCYb3qtKGZKKMRBPmgZo7I11CTY9vQzNiVCsddF+NJZOCexBdZTDuaF8C6m6MeDWGz2O 84EyKhN+R+tiDg6ry5Zdvs1k+t+MXLVaym1rOFvDqXWrcWGnmUJq66oAo/+lFVTGDDMF spjhWPgr0OSF5/bsWCOb6rye4DPS2NfoUmaAx1gMD9nI4erOCP2ngTq0bCkfJk765ytn Iewy/sCoyf6ANJUcQL/6zxpYlfx24FeRknl5AUVm3MfO92mZ/01G0gFEuI71TSFYPAqw rVKg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=WtMX72KLBH/oqLRTjw6ZoQ9HphAQ86EWlsGtUM1biLY=; b=ToVNskN6KUo+ZOoOHniac9/7mxIxIBk9lLfNRh0wg5YU50+gRv+TYPixYKxOkSi7eg PbCaH5Ub1GAODk/msi1QWjGQTNH76/KMeT8Srlf/aHUT+BT5QQrSn2yZMMCmB15bjKe7 bjvk9IRIVgBslymmjKZUJaMncpaFYv/Mlu7gJvN1JZbfgyrBiGO9dAR6HKDoWVlBImRm 1fQDzmaNik3VVynNrej/OpOoAlEFuXS9FN/PMY+GJPFMQW8G/vk5Itf/solxe6W/u9zW K2DzeYB5hiYxELj5/A8nDEQMAPOUkzPV8v6dHTQHVaheUePgOTk9I6soB+33Lc3S6+qn MvJg== X-Gm-Message-State: ACrzQf25vYSzDoEf9XsEKqTA4qjoO1P2Ub++7P5eZe8PX3okaEGR+AsL BVSXhqTju5MnnJsYtopbsN/HAQ== X-Google-Smtp-Source: AMsMyM5ARqNAYBYplnOqSjtUrbcf4MWsV3uP/gieV6dYA025Qv5ID/SBR6x37ttDQse4hV7lX8FXIg== X-Received: by 2002:a05:622a:138b:b0:39c:eb5a:5c33 with SMTP id o11-20020a05622a138b00b0039ceb5a5c33mr24003935qtk.412.1666528776446; Sun, 23 Oct 2022 05:39:36 -0700 (PDT) Received: from [192.168.1.8] ([64.57.193.93]) by smtp.gmail.com with ESMTPSA id u30-20020a37ab1e000000b006ef0350db8asm7299556qke.128.2022.10.23.05.39.34 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 23 Oct 2022 05:39:35 -0700 (PDT) Message-ID: Date: Sun, 23 Oct 2022 08:39:34 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.0 Subject: Re: [PATCH 2/2] dt-bindings: pwm: mediatek: Add compatible string for MT7986 To: Daniel Golle Cc: Rob Herring , linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Thierry Reding , linux-mediatek@lists.infradead.org, Krzysztof Kozlowski , =?UTF-8?Q?Uwe_Kleine-K=c3=b6nig?= , Matthias Brugger , linux-arm-kernel@lists.infradead.org References: <20221021222338.GA565200-robh@kernel.org> <5182e3c4-9e5e-2c36-408b-9029c65c8803@linaro.org> Content-Language: en-US From: Krzysztof Kozlowski In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 23/10/2022 08:24, Daniel Golle wrote: > Hi Krzysztof, > > On Sat, Oct 22, 2022 at 12:35:25PM -0400, Krzysztof Kozlowski wrote: >> On 21/10/2022 18:58, Daniel Golle wrote: >>> On Fri, Oct 21, 2022 at 05:23:38PM -0500, Rob Herring wrote: >>>> On Fri, Oct 21, 2022 at 04:25:18PM +0100, Daniel Golle wrote: >>>>> Add new compatible string for MT7986 PWM. >>>>> >>>>> Signed-off-by: Daniel Golle >>>>> --- >>>>> Documentation/devicetree/bindings/pwm/pwm-mediatek.txt | 1 + >>>>> 1 file changed, 1 insertion(+) >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/pwm/pwm-mediatek.txt b/Documentation/devicetree/bindings/pwm/pwm-mediatek.txt >>>>> index 554c96b6d0c3e0..6f4e60c9e18b81 100644 >>>>> --- a/Documentation/devicetree/bindings/pwm/pwm-mediatek.txt >>>>> +++ b/Documentation/devicetree/bindings/pwm/pwm-mediatek.txt >>>>> @@ -8,6 +8,7 @@ Required properties: >>>>> - "mediatek,mt7623-pwm": found on mt7623 SoC. >>>>> - "mediatek,mt7628-pwm": found on mt7628 SoC. >>>>> - "mediatek,mt7629-pwm": found on mt7629 SoC. >>>>> + - "mediatek,mt7986-pwm": found on mt7986 SoC. >>>> >>>> This version of the PWM h/w is not compatible with any of the existing >>>> chips? If it is, it should have a fallback compatible. >>> >>> No, it is unique because it comes with just 2 PWM channels. >>> Otherwise the driver behaves just like for MT8183 (4 channels) or >>> MT8365 (3 channels) which also got distinct compatible strings. >> >> Then something would be here compatible. E.g. If you bound MT8183 with >> mt7986-pwm compatible, would you get working device with two channels? > > Yes, but I'd see another 2 channels which do not work, accessing them > may even cause problems (I haven't tried that) as it means accessing > an undocumented memory range of the SoC which we in general we > shouldn't be messing around with. Why on MT8183 there would be undocumented memory? Where is undocumented memory? > > Also note that this case is the same as MT8183 vs. MT8365, they got > distinct compatible strings and also for those two the only difference > is the number of channels. So why they are not made compatible? > >> >> If so, they are compatible. > > By that definition you should remove the additional compatible for > MT8365 or rather, it should have been rejected for the same argument. > > I'm talking about > commit fe00faee8060402a3d85aed95775e16838a6dad2 > commit 394b517585da9fbb2eea2f2103ff47d37321e976 This is a pattern spreading in several Mediatek bindings and we already commented on new patches. I don't know why people working on Mediatek do not mark pieces compatible. Best regards, Krzysztof