From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932380AbbENLEk (ORCPT ); Thu, 14 May 2015 07:04:40 -0400 Received: from smarthost01c.mail.zen.net.uk ([212.23.1.5]:55476 "EHLO smarthost01c.mail.zen.net.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932242AbbENLEi (ORCPT ); Thu, 14 May 2015 07:04:38 -0400 Message-ID: <1431601471.2881.36.camel@linaro.org> Subject: Re: [PATCH 2/5] arm64: Juno: Split juno.dts into juno-base.dtsi and juno.dts. From: "Jon Medhurst (Tixy)" To: Liviu Dudau Cc: Arnd Bergmann , Olof Johansson , Rob Herring , Mark Rutland , Ian Campbell , Marc Zyngier , Catalin Marinas , Will Deacon , Sudeep Holla , devicetree , LAKML , LKML Date: Thu, 14 May 2015 12:04:31 +0100 In-Reply-To: <20150514103040.GN2345@e106497-lin.cambridge.arm.com> References: <1431537092-19597-1-git-send-email-Liviu.Dudau@arm.com> <1431537092-19597-3-git-send-email-Liviu.Dudau@arm.com> <1431596142.2881.13.camel@linaro.org> <20150514103040.GN2345@e106497-lin.cambridge.arm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.9-1+b1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Originating-smarthost01c-IP: [82.69.122.217] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2015-05-14 at 11:30 +0100, Liviu Dudau wrote: > On Thu, May 14, 2015 at 10:35:42AM +0100, Jon Medhurst (Tixy) wrote: [...] > > > > What criteria were used to select the contents of juno-base.dtsi? > > From what I can see, the stuff left out of base is still the same for r0 > > and r1 (cpu, pmu, memory, psci!). [...] > > There are potential differences. Cortex-A53 cluster in r1 has limited > CPUfreq functionality due to a chip errata and there were talks internally > to actually disable it, hence the reason for keeping CPUs outside the > juno-base.dtsi. r2 will have a different set of big CPUs as well, so this > is preparing for the future as well. > > PMU are linked to the CPUs, hence the reason they stayed. As for the > memory and psci nodes the thinking behind it was mostly to allow for > ACPI to make changes there, but it does look now like retrofitting an > explanation to something that I did not give too much thought at that > moment. I guess my concern was motivated by the selfish aspect of having to maintain a bunch of out-of-tree Juno patches (like cpuidle and cpufreq related DT updates) and having to duplicate those in more than one DT, and also having backport DT reorgs like this patch. Of course, none of that should be a consideration in deciding what goes into mainline, I just wanted to make sure there was a reason for the patch. -- Tixy From mboxrd@z Thu Jan 1 00:00:00 1970 From: tixy@linaro.org (Jon Medhurst (Tixy)) Date: Thu, 14 May 2015 12:04:31 +0100 Subject: [PATCH 2/5] arm64: Juno: Split juno.dts into juno-base.dtsi and juno.dts. In-Reply-To: <20150514103040.GN2345@e106497-lin.cambridge.arm.com> References: <1431537092-19597-1-git-send-email-Liviu.Dudau@arm.com> <1431537092-19597-3-git-send-email-Liviu.Dudau@arm.com> <1431596142.2881.13.camel@linaro.org> <20150514103040.GN2345@e106497-lin.cambridge.arm.com> Message-ID: <1431601471.2881.36.camel@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, 2015-05-14 at 11:30 +0100, Liviu Dudau wrote: > On Thu, May 14, 2015 at 10:35:42AM +0100, Jon Medhurst (Tixy) wrote: [...] > > > > What criteria were used to select the contents of juno-base.dtsi? > > From what I can see, the stuff left out of base is still the same for r0 > > and r1 (cpu, pmu, memory, psci!). [...] > > There are potential differences. Cortex-A53 cluster in r1 has limited > CPUfreq functionality due to a chip errata and there were talks internally > to actually disable it, hence the reason for keeping CPUs outside the > juno-base.dtsi. r2 will have a different set of big CPUs as well, so this > is preparing for the future as well. > > PMU are linked to the CPUs, hence the reason they stayed. As for the > memory and psci nodes the thinking behind it was mostly to allow for > ACPI to make changes there, but it does look now like retrofitting an > explanation to something that I did not give too much thought at that > moment. I guess my concern was motivated by the selfish aspect of having to maintain a bunch of out-of-tree Juno patches (like cpuidle and cpufreq related DT updates) and having to duplicate those in more than one DT, and also having backport DT reorgs like this patch. Of course, none of that should be a consideration in deciding what goes into mainline, I just wanted to make sure there was a reason for the patch. -- Tixy