From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: Re: [PATCH 2/2] ARM: EXYNOS: add cpuidle-exynos.max_states kernel parameter Date: Mon, 02 Sep 2013 11:41:29 +0200 Message-ID: <7429815.RzOHxBbusd@amdc1032> References: <4002844.4ZqqJexTv4@amdc1032> <52245239.4000903@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7Bit Return-path: In-reply-to: <52245239.4000903@linaro.org> Sender: linux-samsung-soc-owner@vger.kernel.org To: Daniel Lezcano Cc: Kukjin Kim , "Rafael J. Wysocki" , Tomasz Figa , Amit Daniel Kachhap , linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org List-Id: linux-pm@vger.kernel.org On Monday, September 02, 2013 10:54:17 AM Daniel Lezcano wrote: > On 08/30/2013 12:21 PM, Bartlomiej Zolnierkiewicz wrote: > > Add "cpuidle-exynos.max_states=" parameter to allow user to specify > > the maximum of allowed CPU idle states for ARM EXYNOS cpuidle driver. > > > > This change is needed because C1 state (AFTR mode) is often not able > > to work properly due to incompatibility with some bootloader versions. > > > > Usage examples: > > > > "cpuidle-exynos.max_states=1" disables C1 state (AFTR mode). > > > > "cpuidle-exynos.max_states=0" disables the driver completely. > > > > Signed-off-by: Bartlomiej Zolnierkiewicz > > Signed-off-by: Kyungmin Park > > Cc: Tomasz Figa > > Cc: Amit Daniel Kachhap > > There is a max_cstate option for acpi and intel idle. There is also the > cpuidle.off=1 option. As the semantic is the same, I think adding a > common cpuidle option usable for all the drivers is better. I thought about making the option common for all cpuidle drivers first but due to support for multiple cpuidle drivers on one machine (i.e. big.LITTLE), per-driver option looked like a better approach. Should I make the option common and not worry about multiple drivers on one machine support? Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics