From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933280AbbENNLU (ORCPT ); Thu, 14 May 2015 09:11:20 -0400 Received: from eu-smtp-delivery-143.mimecast.com ([146.101.78.143]:41401 "EHLO eu-smtp-delivery-143.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932797AbbENNLQ convert rfc822-to-8bit (ORCPT ); Thu, 14 May 2015 09:11:16 -0400 Date: Thu, 14 May 2015 14:11:12 +0100 From: Liviu Dudau To: "Jon Medhurst (Tixy)" Cc: Arnd Bergmann , Olof Johansson , Rob Herring , Mark Rutland , Ian Campbell , Marc Zyngier , Catalin Marinas , Will Deacon , Sudeep Holla , devicetree , LAKML , LKML Subject: Re: [PATCH 2/5] arm64: Juno: Split juno.dts into juno-base.dtsi and juno.dts. Message-ID: <20150514131112.GQ2345@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> <1431601471.2881.36.camel@linaro.org> MIME-Version: 1.0 In-Reply-To: <1431601471.2881.36.camel@linaro.org> User-Agent: Mutt/1.5.22 (2013-10-16) X-OriginalArrivalTime: 14 May 2015 13:11:12.0369 (UTC) FILETIME=[7366E610:01D08E47] X-MC-Unique: rQsXItxpSxi4hH8cK-xCMg-1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 14, 2015 at 12:04:31PM +0100, Jon Medhurst (Tixy) wrote: > 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. You are probably the best placed engineer to offer feedback on these patches, as it will affect you in the downstream. Given that cpufreq will have limited ranges for Juno r1 (~200MHz spread) and that HMP/EAS will not be working optimally on R1, do you still want to see the CPUs nodes moved into juno-base.dtsi? Best regards, Liviu > > -- > Tixy > > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯ From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liviu Dudau Subject: Re: [PATCH 2/5] arm64: Juno: Split juno.dts into juno-base.dtsi and juno.dts. Date: Thu, 14 May 2015 14:11:12 +0100 Message-ID: <20150514131112.GQ2345@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> <1431601471.2881.36.camel@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1431601471.2881.36.camel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> Content-Disposition: inline Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Jon Medhurst (Tixy)" Cc: Arnd Bergmann , Olof Johansson , Rob Herring , Mark Rutland , Ian Campbell , Marc Zyngier , Catalin Marinas , Will Deacon , Sudeep Holla , devicetree , LAKML , LKML List-Id: devicetree@vger.kernel.org On Thu, May 14, 2015 at 12:04:31PM +0100, Jon Medhurst (Tixy) wrote: > 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= : > [...] > > >=20 > > > 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!). > [...] > >=20 > > There are potential differences. Cortex-A53 cluster in r1 has limit= ed > > CPUfreq functionality due to a chip errata and there were talks int= ernally > > to actually disable it, hence the reason for keeping CPUs outside t= he > > juno-base.dtsi. r2 will have a different set of big CPUs as well, s= o this > > is preparing for the future as well. > >=20 > > PMU are linked to the CPUs, hence the reason they stayed. As for th= e > > memory and psci nodes the thinking behind it was mostly to allow fo= r > > 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 th= at > > moment. >=20 > 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 cpufre= q > 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 o= f > that should be a consideration in deciding what goes into mainline, I > just wanted to make sure there was a reason for the patch. You are probably the best placed engineer to offer feedback on these pa= tches, as it will affect you in the downstream. Given that cpufreq will have limited ranges for Juno r1 (~200MHz spread= ) and that HMP/EAS will not be working optimally on R1, do you still want to = see the CPUs nodes moved into juno-base.dtsi? Best regards, Liviu >=20 > --=20 > Tixy >=20 >=20 --=20 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- =C2=AF\_(=E3=83=84)_/=C2=AF -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liviu.Dudau@arm.com (Liviu Dudau) Date: Thu, 14 May 2015 14:11:12 +0100 Subject: [PATCH 2/5] arm64: Juno: Split juno.dts into juno-base.dtsi and juno.dts. In-Reply-To: <1431601471.2881.36.camel@linaro.org> 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> <1431601471.2881.36.camel@linaro.org> Message-ID: <20150514131112.GQ2345@e106497-lin.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, May 14, 2015 at 12:04:31PM +0100, Jon Medhurst (Tixy) wrote: > 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. You are probably the best placed engineer to offer feedback on these patches, as it will affect you in the downstream. Given that cpufreq will have limited ranges for Juno r1 (~200MHz spread) and that HMP/EAS will not be working optimally on R1, do you still want to see the CPUs nodes moved into juno-base.dtsi? Best regards, Liviu > > -- > Tixy > > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ?\_(?)_/?