From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH v9 4/6] ARM: Exynos: switch to using generic cpufreq driver for Exynos4210/5250/5420 Date: Mon, 25 Aug 2014 08:32:01 -0700 Message-ID: <7h8umc60we.fsf@paris.lan> References: <1406707663-16656-1-git-send-email-thomas.ab@samsung.com> <1406707663-16656-5-git-send-email-thomas.ab@samsung.com> <53DA8BB9.6020702@samsung.com> <53DA8D85.3050106@gmail.com> <7hbnrc6px3.fsf@paris.lan> <53F7DA13.6090305@gmail.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: (Chander Kashyap's message of "Mon, 25 Aug 2014 17:45:07 +0530") Sender: linux-samsung-soc-owner@vger.kernel.org To: Chander Kashyap Cc: Tomasz Figa , Lukasz Majewski , Kukjin Kim , Mike Turquette , Heiko =?utf-8?Q?St=C3=BCbner?= , "linux-pm@vger.kernel.org" , Viresh Kumar , Bartlomiej Zolnierkiewicz , amit.kucheria@linaro.org, Chanwoo Choi , Thomas Abraham , "linux-samsung-soc@vger.kernel.org" , linaro-kernel@lists.linaro.org, "linux-arm-kernel@lists.infradead.org" , Marek Szyprowski List-Id: linux-pm@vger.kernel.org Hi Chander, Chander Kashyap writes: [...] >>> I'm trying it on the 5800/Chromebook2 and it's not terribly stable. I'm >>> testing along with CPUidle, so there may be some untested interactions >>> there as it seems a bit more stable without CPUidle enabled. >>> >>> I'd love to hear from anyone else that's testing CPUidle and CPUfreq >>> together big.LITTLE 5420/5800, with or without the switcher. > > I have tested this patch series on SMDK5420 with cpuidle (with and > without b.L switcher enabled). > > As of now voltage scaling support is not there in generic big-little > cpufreq driver (arm_big_little.c). > Hence need to tie arm and kfc voltages to highest level for testing. > Without this change stability issues are there, but with this change > everything is stable. Can you clarify how you're setting the voltages to ensure stability? Tomasz, I didn't mean to suggest this isn't ready for mainline. For the 5420/5800 it seems cpufreq support is a new feature, so this isn't a regression against previous (mainline) behavior. Maybe the big.LITTLE cpufreq support should've been separated out from the cleanup since it's more of a new feature, but that's up to you. Kevin