From mboxrd@z Thu Jan 1 00:00:00 1970 From: Javier Martinez Canillas Subject: Re: CPUIdle for Exynos5422 Odroid-XU3/XU4 boards. Date: Fri, 21 Aug 2015 09:21:41 +0200 Message-ID: <55D6D185.5070909@osg.samsung.com> References: <55D5FBDB.4040904@free.fr> <55D676E8.8020802@samsung.com> <55D6A23C.5020403@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from lists.s-osg.org ([54.187.51.154]:58989 "EHLO lists.s-osg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750798AbbHUHVq (ORCPT ); Fri, 21 Aug 2015 03:21:46 -0400 In-Reply-To: <55D6A23C.5020403@samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Krzysztof Kozlowski , Anand Moon Cc: Daniel Lezcano , Kukjin Kim , Bartlomiej Zolnierkiewicz , "linux-samsung-soc@vger.kernel.org" , Przemyslaw Marczak [Adding Przemyslaw Marczak who was working on porting Odroid BL1/BL2/SPL] Hello, On 08/21/2015 05:59 AM, Krzysztof Kozlowski wrote: > On 21.08.2015 12:41, Anand Moon wrote: >> Hi Krzysztof, >> >> On 21 August 2015 at 06:25, Krzysztof Kozlowski wrote: >>> On 21.08.2015 03:15, Anand Moon wrote: >>>> Hi Daniel, >>>> >>>> On 20 August 2015 at 21:40, Daniel Lezcano wrote: >>>>> On 08/20/2015 12:54 PM, Anand Moon wrote: >>>>>> >>>>>> Hello Krzysztof/Kukjim, >>>>>> >>>>>> CPUIdle seen to be not working for Exynos5422 Odroid boards. >>>>>> >>>>>> Is their any way this feature will be implemented in the future. >>>>> >>>>> >>>>> Yeah a good willing to fix the bl1. More than one year asking for that ! >>>>> nooo way !! >>>>> >>>>> Your answer is at the end of >>>>> http://lists.infradead.org/pipermail/linux-arm-kernel/2015-June/350632.html >>>>> >>>>> >>>> >>>> Thanks for the explanation. >>>> >>>> I was just referring following the source code. >>>> >>>> https://github.com/hardkernel/linux/blob/odroidxu3-3.10.y/arch/arm/mach-exynos/cpuidle-exynos5422.c >>>> >>>> It seem that cpufreq and cpuidle go hand in hand. >>> >>> Bartlomiej was working on cpufreq for Exynos542x: >>> http://lkml.iu.edu/hypermail/linux/kernel/1504.2/03139.html >>> >>> It would be nice to have also cpuidle and suspend features working on >>> Exynos542x family but this depends on firmware. Some time ago I >>> struggled with suspend on Arndale Octa (Exynos5420) and I failed. I >>> think the firmware is the issue here. There were a lot of Suspend-to-RAM bug fixes lately mostly related to critical clocks being gated. It would be nice to give a try on recent kernels and see if is still not working. >>> >>> Actually I am not sure what is your question Anand. You are asking if >>> someone plans to do this? >> >> Yes I am asking are their plans to implement cpufreq and cpuidle simultaneously. > > There are no obstacles for implementing them simultaneously so the > question is rather who plans to do the cpuidle driver for Exynos542x? I If the firmware is in a good shape (unfortunately as mentioned by Daniel, the one in the Odroids are not) then the generic ARM big.LITTLE CPUidle driver (CONFIG_ARM_BIG_LITTLE_CPUIDLE) should work. It is at least working for me on the Exynos5800 based Peach Pi Chromebook: $ cat /sys/devices/system/cpu/cpuidle/current_driver big_idle $ cat /sys/devices/system/cpu/cpu0/cpuidle/state*/name WFI C1 $ cat /sys/devices/system/cpu/cpu0/cpuidle/state*/usage 7745 10578 > don't... at least in nearby future. If I had some spare time then > probably I would try to make suspend working. > Suspend-to-RAM is at least working on the Exynos5420 and Exynos5800 Chromebooks. As you mentioned it may depend on the firmware so that does not hold true for all the Exynos5420/5422/5800 boards but it would be good to know what is the causing S2R to fail. > Best regards, > Krzysztof > Best regards, -- Javier Martinez Canillas Open Source Group Samsung Research America