From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2A413267B1A; Tue, 25 Feb 2025 12:07:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740485243; cv=none; b=G0eIXlXCal/4tOARTJWrjpNdoeLX1nwe+uC0XdsjcSOObE+TWJY+RbAD+pGSBnlGBWAtMBLg8lwuuEQ7bosOI3PnFzYA9W5KS2pY0nYiQdXWgAL5hYYrNPwF9y4s5GqKaxoVbJekQo/8W7sQ9Z3VWDv2W0A5sL9eY91HdX0oz14= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740485243; c=relaxed/simple; bh=BZgdWO7k4+OKLqpthfS5rJrQuQPttt/GmTiWB7L+cFI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fIVoUSIJLeUwBgUctgZwSOSZiFI8bovhKesnzGIDJg72WHvXsfs+WdfnpXKZpV4CSc5qNpXDflWcsK4d3pqyTvz8cO3O75gSO4nnI8n1epyc01HsuZQBldfrdqaUn5QMNrjwSGN/adgK7vOqbzJoOSmDFyzPOEfz9FMT1A/F95U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D8753152B; Tue, 25 Feb 2025 04:07:37 -0800 (PST) Received: from bogus (e133711.arm.com [10.1.196.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 135943F6A8; Tue, 25 Feb 2025 04:07:18 -0800 (PST) Date: Tue, 25 Feb 2025 12:07:16 +0000 From: Sudeep Holla To: Vincenzo Frascino Cc: Mark Rutland , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Linus Walleij , Sudeep Holla , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Liviu Dudau , Lorenzo Pieralisi , Russell King , Will Deacon , Jessica Clarke Subject: Re: [PATCH v7 00/10] arm64: dts: Add Arm Morello support Message-ID: References: <20250221180349.1413089-1-vincenzo.frascino@arm.com> <58ee2a8d-d3c1-4bc2-92dd-6568f645b01f@arm.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <58ee2a8d-d3c1-4bc2-92dd-6568f645b01f@arm.com> Hi Mark, Thanks for raising valid points/concerns. On Mon, Feb 24, 2025 at 10:08:18AM +0000, Vincenzo Frascino wrote: > Hello Mark, > > On 21/02/2025 18:54, Mark Rutland wrote: > > Hi Vincenzo, > > > > On Fri, Feb 21, 2025 at 06:03:39PM +0000, Vincenzo Frascino wrote: > >> The Morello architecture is an experimental extension to Armv8.2-A, > >> which extends the AArch64 state with the principles proposed in > >> version 7 of the Capability Hardware Enhanced RISC Instructions > >> (CHERI) ISA [1]. > > > > None of the CHERI stuff is supported upstream, so from upstream's PoV > > this is a low-volume dev-board/SoC with an experimental ARMv8.2-A CPU. > > I understand and agree with your concerns. > > Agreed, I have no plans to upstream Morello support beyond the device tree. > > >> This series adds dts support for the Arm Morello System Development > >> Platform. > > > > Do we actually need the dts for this board? > > > > I have one on my desk; it boots vanilla Debian 12 via UEFI + ACPI just > > fine, with the Debian 6.1.0-13-arm64 kernel. > > > > Is there something that we can only do with the DT? i.e. some > > functionality that isn't exposed via ACPI? > > > > How do you expect this DT to be used? > > > > There are functionalities that are not exposed via ACPI, e.g. gpu, dpu, i2c for > the phy, etc. My aim to have upstream support for all the hardware exposed by > the platform. > Does this address some of your concerns ? I do understand some of these are not well addressed in ACPI and hence people use DT as an alternative. > Note: This series contains only the basic infrastructure, the plan is add > progressively more features in the future. > I was thinking of queuing this in -next if all the bindings are acked. Let me know if you still have concerns and would like to avoid getting these merged. I will hold off then. -- Regards, Sudeep