From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dietmar Eggemann Subject: Re: [PATCH 2/4] arm: dts: exynos: add exynos5420 cpu capacity-dmips-mhz information Date: Wed, 6 Sep 2017 12:47:21 +0100 Message-ID: <247b2b4a-c57a-eed9-c16f-fc7f1ef9f64f@arm.com> References: <20170830144120.9312-1-dietmar.eggemann@arm.com> <20170830144120.9312-3-dietmar.eggemann@arm.com> <20170830202650.mdlxy2c3uwuq5vde@kozik-lap> <94c1d6c6-655a-2a63-1f01-06ac45990388@arm.com> <20170903195614.iwe7v6g3xsg7p6nf@kozik-lap> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170903195614.iwe7v6g3xsg7p6nf@kozik-lap> Content-Language: en-GB Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Krzysztof Kozlowski Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-samsung-soc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-renesas-soc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Russell King , Rob Herring , Mark Rutland , Kukjin Kim , Vincent Guittot , Juri Lelli List-Id: devicetree@vger.kernel.org On 03/09/17 20:56, Krzysztof Kozlowski wrote: > On Thu, Aug 31, 2017 at 11:36:07AM +0100, Dietmar Eggemann wrote: >> On 30/08/17 21:26, Krzysztof Kozlowski wrote: >>> On Wed, Aug 30, 2017 at 03:41:18PM +0100, Dietmar Eggemann wrote: [...] >>>> The patch has been tested on Samsung Chromebook 2 13" (peach-pi, Exynos >>>> 5800). >>>> >>>> $ cat /sys/devices/system/cpu/cpu*/cpu_capacity >>>> 1024 >>>> 1024 >>>> 1024 >>>> 1024 >>>> 389 >>>> 389 >>>> 389 >>>> 389 >>> >>> I am missing something... shouldn't this be 539? Or is it scaled with >>> the clock-frequency (1 GHz) value? >> >> Yeah, the capacity-dmips-mhz dt value of 539 for the little cpus is >> scaled by 1.3/1.8 (max cpu capacity/ system wide max cpu capacity): >> >> 539 * 1.3/1.8 = 389 >> >> This max cpu capacity scaling is part of both solutions, the 'cpu >> capacity-dmips-mhz' and the 'cpu_efficiency/clock-frequency dt property' >> one. >> >> The (original*) cpu capacity on a heterogeneous platform expresses uArch >> and max cpu frequency differences between the (logical) cpus of the >> system. >> >> * not further reduced by rt and/or irq pressure. >> >> [...] > > Thanks for explanation, looks fine for me. I'll take it after merge > window. Nice, since the 'cpu capacity-dmips-mhz' is already supported for arm (and used by TC2 (vexpress-v2p-ca15_a7.dts)) this can be done independently of the actual removal of the 'cpu_efficiency/clock-frequency dt property' solution in patch 1/4. [..] -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html