From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 D141B468C22; Thu, 27 Aug 2026 12:59:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787835567; cv=none; b=gEYJYALTGE3+60YeJXgu4YjINsELSifSRKL68rDue/BS7qH3roRYt0TLSWj9HBTxNeJ60U5jD4+NUjbCFEvSE3riLih6I6oJzWAzUjY/PAfglejxv+svHcNxchNEUHUBqUj2MhMWX7KQbuHxZeAZvs30kSdcD4vPcTQy5kA0QaA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787835567; c=relaxed/simple; bh=BtvWV6bld2ba6TREhgL7Z9HI0Ln0mrJ078noHXO8Q4s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=iGSZDgdmvJYi84d5nvgAvLuxtqUC5AjaS0HNYKbqWDovSizKEqaF6V75auRqf1p20RWd1h+/ah95ooMVF9kIHZliIAbw3+x1W4uiAAkVoBP+A3ZvjjXCJW6vvjgAdEa+7SCpA5Q7TpaEtHVoeGoD8NXRGGhQhuhqqzkGLzgF/Jw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iartQjrd; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iartQjrd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B9DD1F000E9; Thu, 27 Aug 2026 12:59:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787835556; bh=b+1HOJ3x4l1XMOH28+iaXuruI8JflIZTg9npiF7QHFI=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=iartQjrdAkHCpsnS22R3ITP1AJP0TlXreWVDzCAPlPvtsGdTFLmpEdRPEs3GUrtHo Vz2FFBEYDD3eI6EqVug2asPBzJrWnGp+b9NMUs/cSKVHMwQ3dmOTFCetdcdg3eZA0L R18z5oEqqBZowufsPjG7oyqF0aKukNNsKd6oZ9/pYp2Afb5PuJnavp2gRgxj7VFVa1 YCjG8nXky9e8101XTlnHqay55Csvyng3Dr5sjILdntL76RK9UICtEOn46qk8GLiWtw ZCRMb4RoMMAWZKJrX9A1EVYIkjJzo1MU2TfUhFtkupD1DrIhloaB9taSYhmmoaup4N mFFusZiuw3n5w== Date: Thu, 27 Aug 2026 13:59:06 +0100 From: Lee Jones To: Bartosz Golaszewski Cc: Ulf Hansson , Lorenzo Pieralisi , Arnd Bergmann , Bjorn Andersson , Sebastian Reichel , Rob Herring , Souvik Chakravarty , Krzysztof Kozlowski , Andy Yan , Matthias Brugger , Mark Rutland , Conor Dooley , Konrad Dybcio , John Stultz , Moritz Fischer , "Rafael J. Wysocki" , Daniel Lezcano , Christian Loehle , Ulf Hansson , Pavan Kondeti , Sudeep Holla , Florian Fainelli , Krzysztof Kozlowski , Dmitry Baryshkov , Mukesh Ojha , Andre Draszik , Greg Kroah-Hartman , Kathiravan Thirumoorthy , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, mfd@lists.linux.dev, Srinivas Kandagatla , Bartosz Golaszewski , Shivendra Pratap Subject: Re: [PATCH v24 04/12] mfd: psci-mfd: Add PSCI MFD driver for cpuidle-psci-domain cell Message-ID: <20260827125906.GJ770273@google.com> References: <20260803-arm-psci-system_reset2-vendor-reboots-v24-0-889281373870@oss.qualcomm.com> <20260803-arm-psci-system_reset2-vendor-reboots-v24-4-889281373870@oss.qualcomm.com> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Wed, 26 Aug 2026, Bartosz Golaszewski wrote: > On Fri, 21 Aug 2026 14:59:49 +0200, Ulf Hansson > said: > > On Mon, Aug 3, 2026 at 11:45 AM Shivendra Pratap > > wrote: > >> > >> PSCI has multiple kernel consumers, such as cpuidle-psci-domain. > >> Currently, both the PSCI core driver and cpuidle-psci-domain bind > >> directly to the same PSCI node "arm,psci-1.0". Additional consumers, if > >> introduced, would also need to bind in the same way, leading to several > >> drivers attached to a single device node. > >> > >> Introduce a PSCI MFD driver that binds to "arm,psci-1.0" and registers > >> PSCI child cells. As the first user, register cpuidle-psci-domain as a > >> child cell. > > > > I don't think PSCI should be modeled as an MFD device with childrens. > > > > Instead, this looks rather like a better fit for the auxiliary > > bus/driver. Please consider using that instead. > > > > Hi Uffe! > > Since I was the one to suggest MFD - would you mind providing more arguments > in favor of your preferred option? > > My reasoning for MFD was that it is indeed a device that provides multiple > functionalities, of which cpuidle is not really he main one even though it's > currently the only driver binding to this node. > > In any case, we'd need a "core" driver binding to the psci node and with > multiple auxiliary devices with their own drivers, we'd end up reimplementing > MFD. Ulf could be correct. MFD is usually reserved for real devices, whereas the aux is a little more loose. Please consider it as an option. -- Lee Jones