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 D2D94C61DC6 for ; Thu, 27 Aug 2026 12:59:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: 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=b+1HOJ3x4l1XMOH28+iaXuruI8JflIZTg9npiF7QHFI=; b=V/YgPaudriT2At9ii9xu2lmhf/ 6uu8pYIBChvutjoUdEwRaEoC2WB3LCPACVhh8AYrt9agMY8VXh2DVvflm5Mn70PZ64nmXnMsI3FWC Kea2LigUtu91J1RVBr2kpqO69aDb6gK0e3FHnqY8RCeKz5FD0sdDvQWWZLQElnaH5WFZlFLv4Swmc PU813mL3FRnO2KMniyaB746LeheW/ta6Inffo3SeR2cTFff8vpY2DyJuM7RGeuX1Mt3AD5BCy2Fmc 0Pp6JpFqg8v3bEr2Xo9LmopYvL6rF/ME9Izlx2W80Zx2yFIrwqW7S3466qgmti1CQYduamqFKV/EZ ppL16V5Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wzZhP-000000040cT-1Nh4; Thu, 27 Aug 2026 12:59:19 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wzZhN-000000040cN-0UAo for linux-arm-kernel@lists.infradead.org; Thu, 27 Aug 2026 12:59:17 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 499B7600D2; Thu, 27 Aug 2026 12:59:16 +0000 (UTC) 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> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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