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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AFD50C77B7A for ; Tue, 23 May 2023 06:35:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:References: In-Reply-To:Subject:CC:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=yZigIxgLgEHqx+5ecYM2itDqcYjoN2gXwzFoI7xhGTg=; b=srgP5eHsYKtevD mRFh7VhrqXQk0yHIc3A84kDutkfHEbZOsDj/Om6Z2yo4wkJj6M5sNzzyJhAKxeIrC/p+uf14Y0UAh qHs3xl9y7b0bvcwfqReB2afLE9edpLBatqOlLgtHGCKtir7tB0aJ3qOrWA0Q9Yg9rBh9aIML/PAKF 2JoClw3No5GjIZ6Q2tTj2CyjJ0uxtY81Ay2TuLmNgS9dV8jBAmxjaHNyEA4aYCvzIf69xj+uHROp8 VhfCFQZ0pwOyZqP/660lRFwUwKVZX6o0StJoT0f1BRJxNm9+6DUnjJaMWO4z6xZhJuqTJH/0xw2Bl dC4/y13rsVX4D2ci3G9Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q1Lbl-0095Oe-0c; Tue, 23 May 2023 06:34:57 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1q1KRK-008wiU-0h; Tue, 23 May 2023 05:20:09 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2062962462; Tue, 23 May 2023 05:20:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C835FC433D2; Tue, 23 May 2023 05:20:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684819202; bh=VCOHu+r91RekSvZ+lEnUHnm2c/u+To8APapSLwT3z0M=; h=Date:From:To:List-Id:CC:Subject:In-Reply-To:References:From; b=VibwJcx2lwId8O7YxhtlikOxayiGhjyjJTUq7YuV4ydjTCh3JlTDLA2SjBieq4t/6 IeL0E8NeFfZpixEAOnbldfdOK7LSZuEFayJlKTBDXcFBR3ZEZwfWLl4cIFVHnbMQZl zJAGkZirV9K65cN1FBwQw2VIRaaLQDmiNpzAG+EYoDMJj4aq3DjjRwC0Y90epyApuP bg9ks0fYg3N9Vfb/z1Wq5I5aOmf+Ld1QUqbBDfwQgfDm6BmyNhoUToHxATNqPmche4 BsBOi+hAOsUvsJldEfAFdDTGtn2zrSSbpYkA/284U8yUwKLgAO6vd1Ok5SaxD0g+7u eFt3YwD5dVEKw== Date: Tue, 23 May 2023 06:19:57 +0100 From: Conor Dooley To: Jessica Clarke CC: Krzysztof Kozlowski , soc@kernel.org, Conor Dooley , Arnd Bergmann , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jonathan Corbet , Olof Johansson , Palmer Dabbelt , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Linux Kernel Mailing List , linux-doc@vger.kernel.org, Linux ARM , linux-riscv@lists.infradead.org Subject: Re: [PATCH v1] Documentation/process: add soc maintainer handbook User-Agent: K-9 Mail for Android In-Reply-To: <3B8DFBEF-9EA1-4375-998D-944EA18D3E4E@jrtc27.com> References: <20230515-geometry-olympics-b0556ff8a5f7@spud> <20230522-concrete-unpeeled-7e4718e61b46@spud> <3B8DFBEF-9EA1-4375-998D-944EA18D3E4E@jrtc27.com> Message-ID: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230522_222006_336769_9583E274 X-CRM114-Status: GOOD ( 15.96 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 23 May 2023 01:32:49 IST, Jessica Clarke wrote: >On 22 May 2023, at 22:34, Conor Dooley wrote: >> >> On Tue, May 16, 2023 at 10:31:19AM +0200, Krzysztof Kozlowski wrote: >>> On 15/05/2023 21:20, Conor Dooley wrote: >> >>>> +devicetree ABI stability >>>> +~~~~~~~~~~~~~~~~~~~~~~~~ >>>> + >>>> +Perhaps one of the most important things to highlight is that dt-bindings >>>> +document the ABI between the devicetree and the kernel. Once dt-bindings have >>>> +been merged (and appear in a release of the kernel) they are set in stone, and >>>> +any changes made must be compatible with existing devicetrees. This means that, >>>> +when changing properties, a "new" kernel must still be able to handle an old >>>> +devicetree. For many systems the devicetree is provided by firmware, and >>>> +upgrading to a newer kernel cannot cause regressions. Ideally, the inverse is >>>> +also true, and a new devicetree will also be compatible with an old kernel, >>>> +although this is often not possible. >>> >>> I would prefer to skip it and instead: enhance >>> Documentation/devicetree/bindings/ABI.rst and then reference it here. >>> >>>> + >>>> +If changes are being made to a devicetree that are incompatible with old >>>> +kernels, the devicetree patch should not be applied until the driver is, or an >>>> +appropriate time later. Most importantly, any incompatible changes should be >>>> +clearly pointed out in the patch description and pull request, along with the >>>> +expected impact on existing users. >> >> I'm not really sure that I like this truncated section so much, but here >> it is... I kept the last paragraph intact as it does not talk about the >> ABI, but rather exceptions of submaintainers. >> >> devicetree ABI stability >> ~~~~~~~~~~~~~~~~~~~~~~~~ >> >> Perhaps one of the most important things to highlight is that dt-bindings >> document the ABI between the devicetree and the kernel. Please see >> :ref:`devicetree-abi` for devicetree ABI rules. >> >> If changes are being made to a devicetree that are incompatible with old >> kernels, the devicetree patch should not be applied until the driver is, or an >> appropriate time later. Most importantly, any incompatible changes should be >> clearly pointed out in the patch description and pull request, along with the >> expected impact on existing users. > >Do you have an opinion on acknowledging the existence of other OSes here? I think that is fair. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel