From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krzysztof Kozlowski Subject: Re: [PATCH v5 3/7] ARM: dts: Exynos542x/5800: add CPU OPP properties Date: Fri, 11 Dec 2015 13:53:26 +0900 Message-ID: <566A56C6.2000503@samsung.com> References: <1449766729-435-1-git-send-email-b.zolnierkie@samsung.com> <1449766729-435-4-git-send-email-b.zolnierkie@samsung.com> <20151211031646.GL3612@ubuntu> <566A4231.9050608@osg.samsung.com> <20151211033253.GN3612@ubuntu> <566A4A60.8060402@samsung.com> <20151211041349.GO3612@ubuntu> <566A4E82.3040203@samsung.com> <20151211043802.GP3612@ubuntu> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from mailout2.w1.samsung.com ([210.118.77.12]:23035 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751598AbbLKExh (ORCPT ); Thu, 10 Dec 2015 23:53:37 -0500 In-reply-to: <20151211043802.GP3612@ubuntu> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Viresh Kumar , Rob Herring Cc: Javier Martinez Canillas , Bartlomiej Zolnierkiewicz , Thomas Abraham , Sylwester Nawrocki , Mike Turquette , Kukjin Kim , Kukjin Kim , Ben Gamari , Tomasz Figa , Lukasz Majewski , Heiko Stuebner , Chanwoo Choi , Kevin Hilman , Tobias Jakobi , Anand Moon , linux-samsung-soc@vger.kernel.org, linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Doug Anderson , Andreas Faerber On 11.12.2015 13:38, Viresh Kumar wrote: > On 11-12-15, 13:18, Krzysztof Kozlowski wrote: >> We had such configuration before (before df09df6f9ac3). I don't see any >> benefit in what you described. Where is the "thing" to be fixed? It is >> mixed up. The contiguous ordering is easier to read and more natural. > > This is what you are doing today (keeping on one CPU per cluster to > simplify it): > > cpu0: cpu@0 { > device_type = "cpu"; > compatible = "arm,cortex-a15"; > reg = <0x0>; > clock-frequency = <1800000000>; > cci-control-port = <&cci_control1>; > }; > > cpu4: cpu@100 { > device_type = "cpu"; > compatible = "arm,cortex-a7"; > reg = <0x100>; > clock-frequency = <1000000000>; > cci-control-port = <&cci_control0>; > }; > > > Then you overwrite it with: > > &cpu0 { > device_type = "cpu"; > compatible = "arm,cortex-a7"; > reg = <0x100>; > clock-frequency = <1000000000>; > cci-control-port = <&cci_control0>; > }; > > &cpu4 { > device_type = "cpu"; > compatible = "arm,cortex-a15"; > reg = <0x0>; > clock-frequency = <1800000000>; > cci-control-port = <&cci_control1>; > }; > > > Don't you think this isn't the right way of solving problems? > > The DT overwrite feature isn't there to do such kind of stuff, though > it doesn't stop you from doing that. This is quite ugly, indeed, and it is getting uglier :)... but it does not violate the idea of DT to describe the hardware. Both hardware descriptions - the 5420 and overridden - are entirely correct... because the CPU ordering comes from booting sequence (actually code in IROM decides according to pulled up GPIO gpg2-1). > Either you should keep separate paths for both the SoCs, I like that idea. That makes it much more readable. Thanks for feedback! I will send a patch for that. > or can solve > it the way I suggested earlier. > > This came up because in the current series you are doing this: > > cpu0: cpu@0 { > compatible = "arm,cortex-a15"; > operating-points-v2 = <&cpu0_opp_table>; > }; > > cpu4: cpu@100 { > device_type = "cpu"; > compatible = "arm,cortex-a7"; > operating-points-v2 = <&cpu1_opp_table>; > }; > > > Then you overwrite it with: > > &cpu0 { > compatible = "arm,cortex-a7"; > operating-points-v2 = <&cpu1_opp_table>; > }; > > &cpu4 { > compatible = "arm,cortex-a15"; > operating-points-v2 = <&cpu0_opp_table>; > }; Yes, it is getting uglier with each change... Best regards, Krzysztof