From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from codeconstruct.com.au (pi.codeconstruct.com.au [203.29.241.158]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1F8BC15530C; Thu, 26 Mar 2026 06:07:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.29.241.158 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774505275; cv=none; b=TQPwcms1XOlIHIZYPpeZi4YNSYr5VrMOKLSIYmeC3mBc5wdyMfIs4uMKD94k09PrTeyudttaMOM8P6E+tX6tyMQr2qjC0Ocw9tTr2NOJ4eGofCNZjHJUqCrP6V9O61dt80praVMenjiQuSLfVRimuSeOXhdkC3GJFWzG7IpJ7xU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774505275; c=relaxed/simple; bh=D4BWqwsowftV0uLn6UqEICU6dheuLBTYAGw06kSQO3c=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=rUDlPSfoUXVmo0qNsvGFrCIf6MRrnGSurYRIxyshX0AUUtL4LuWOjptsdDJF2xUTAszIPsXgsA/opgrZp83dmESBscVe2jvAwIN4fHhjGJxwstJ+29SVCZPoxaW3i3y7jd2F6xRyqzNbLWoxg0uauGZeEXEGqX60bk2eSKG3HrY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=codeconstruct.com.au; spf=pass smtp.mailfrom=codeconstruct.com.au; dkim=pass (2048-bit key) header.d=codeconstruct.com.au header.i=@codeconstruct.com.au header.b=khH2mG+u; arc=none smtp.client-ip=203.29.241.158 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=codeconstruct.com.au Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=codeconstruct.com.au Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=codeconstruct.com.au header.i=@codeconstruct.com.au header.b="khH2mG+u" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codeconstruct.com.au; s=2022a; t=1774505272; bh=D4BWqwsowftV0uLn6UqEICU6dheuLBTYAGw06kSQO3c=; h=Subject:From:To:Cc:Date:In-Reply-To:References; b=khH2mG+uBGCYkDqfbI4rBOR+DTt4gDN3awebhhzeDtW0i7D3pFkiOjQbFbo4FjsfX hFlHdj8si7MP1DHnhNbUp3N8c2TsJISpuRilYRg/TpM4rP2me+OoPSM02N69Rh1djq w2M2xXTnQquI/E9IkIhPLX0NXuMtf8GYQbNRPkvyoCkAR4on53/sA7OvI2W66kesbB p1xejc2yVcKPEt1JaD05UqQ9f6ihO5wmxvFWc4QO9pt7c/lf7c9U9JSwiZhVyxk8Yo jYeLz1YCr2Tpx92RMhR2xapSSlCKX0dGwldW/Pwbg8ubyoDFQ1lAR4z8aPKRFs9aHv d1mRbsa8jIfuQ== Received: from [192.168.68.115] (unknown [180.150.112.60]) by mail.codeconstruct.com.au (Postfix) with ESMTPSA id 7CDF76597C; Thu, 26 Mar 2026 14:07:51 +0800 (AWST) Message-ID: Subject: Re: [PATCH v5 2/8] ARM: dts: aspeed: yosemite5: Remove ambiguous power monitor DTS nodes From: Andrew Jeffery To: Kevin Tung Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Joel Stanley , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org, Amithash Prasasd , Kevin Tung , Ken Chen , Leo Yang , Jackson Liu , Daniel Hsu Date: Thu, 26 Mar 2026 16:37:51 +1030 In-Reply-To: References: <20260223-yv5_revise_dts-v5-0-fc913e902488@gmail.com> <20260223-yv5_revise_dts-v5-2-fc913e902488@gmail.com> <73ea41bf341df0e3215c58a029c9ea2386c4ef8a.camel@codeconstruct.com.au> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2-0+deb13u1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Hi Kevin, Sorry for the delay. On Mon, 2026-03-09 at 11:41 -0700, Kevin Tung wrote: > On Tue, Mar 3, 2026 at 6:41=E2=80=AFPM Andrew Jeffery > wrote: > >=20 > > Hi Kevin, > >=20 > > Sorry for the patchy replies so far, but this series bothers me and > > other priorities keep bumping it down the list. > >=20 > > On Mon, 2026-02-23 at 19:17 +0800, Kevin Tung wrote: > > > Two different power monitor devices, using different drivers, reuse > > > I2C addresses 0x40 and 0x45 on bus 10 across Yosemite5 board variants= . > > > Defining these devices statically in the DTS can lead to incorrect > > > driver binding on newer boards when the wrong device is instantiated. > >=20 > > There are effective methods of maintaining devicetrees for variants. > > Why are we choosing to remove information about the platform rather > > than use existing techniques to properly describe them? > >=20 > Hi Andrew, >=20 > This is due to hardware design changes during earlier development > stages, and the fix is expected to remain stable as the design has > matured. > Could you guide me on the best way to maintain devicetrees for > variants? Thank you :) My expectation is your platforms move through several design phases prior to (mass?) production. My suspicion is that you have sent a devicetree for the pre-production design phases, and you're trying to evolve that one devicetree to match the design for whatever current phase you're in. So, ideally: Send a devicetree only for the finalised design. Don't send devicetrees for pre-production designs. If you feel you can't do that for some reason, an alternative is to have a separate .dts file for each phase in the design process. This may sound tedious but it doesn't have to be a burden to maintain. For instance, you can use one or more .dtsi files to describe the common components and relationships for your platform. These .dtsi files are then #included into .dts files as usual. Often .dtsi files are used to isolate different hardware scopes (SoC vs board, for instance), but we're not limited to that, we can use them for the purpose outlined above too. If there are only (very) minor differences, there's also the option of #including another .dts file. From there you can adjust properties or even delete nodes where it makes sense. For example, we maintain a .dts file for the latest revision of the AST2600-EVB, but we also have a separate .dts for the A1 revision with a different regulator setup: - https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/a= rch/arm/boot/dts/aspeed/aspeed-ast2600-evb.dts?h=3Dv7.0-rc5 - https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/a= rch/arm/boot/dts/aspeed/aspeed-ast2600-evb-a1.dts?h=3Dv7.0-rc5 Any of these are better options than this current approach of trying to justify incompatible changes against unclear design boundaries. Andrew