From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: Re: [RFC/PATCH 1/2] cpuidle: Allow idle-states to be disabled at start Date: Wed, 24 Aug 2016 17:06:31 +0200 Message-ID: <57BDB7F7.3090502@linaro.org> References: <48afad7788300482c047fc35e70ca8e4bf31a5ac.1471557381.git.ego@linux.vnet.ibm.com> <57BDB2D8.4080507@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Balbir Singh , "Gautham R. Shenoy" , "Rafael J. Wysocki" , Michael Ellerman , Benjamin Herrenschmidt , Michael Neuling , Paul Mackerras , Vaidyanathan Srinivasan Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Anton Blanchard , linux-pm@vger.kernel.org List-Id: linux-pm@vger.kernel.org On 08/24/2016 04:48 PM, Balbir Singh wrote: > > > On 25/08/16 00:44, Daniel Lezcano wrote: >> On 08/19/2016 12:26 AM, Gautham R. Shenoy wrote: >>> From: "Gautham R. Shenoy" >>> >>> Currently all the idle states registered by a cpu-idle driver are >>> enabled by default. This patch adds a mechanism which allows the >>> driver to hint if an idle-state should start in a disabled state. The >>> cpu-idle core will use this hint to appropriately initialize the >>> usage->disable knob of the CPU device idle state. >> >> Why do you need to do that ? >> > > I think patch 2/2 explains the reason as it uses this infrastructure Ok, let me elaborate the question, I was not clear. Why the userspace can't setup the system environment at boot time by disabling the state instead of adding extra code to disable it at boot time in the kernel and then re-enable it from userspace ? -- Daniel -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog