From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Pitre Subject: Re: [PATCH v4 5/5] arm: exynos: Add MCPM call-back functions Date: Fri, 2 May 2014 14:37:42 -0400 (EDT) Message-ID: References: <1398528348-21214-6-git-send-email-a.kesavan@samsung.com> <1399044359-15784-1-git-send-email-a.kesavan@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Andrew Bresticker Cc: Mark Rutland , devicetree@vger.kernel.org, Abhilash Kesavan , Kukjin Kim , Arnd Bergmann , Tomasz Figa , daniel.lezcano@linaro.org, Will Deacon , Rob Herring , Grant Likely , Lorenzo Pieralisi , thomas.ab@samsung.com, Abhilash Kesavan , Dave Martin , "linux-arm-kernel@lists.infradead.org" , inderpal.s@samsung.com List-Id: devicetree@vger.kernel.org On Fri, 2 May 2014, Andrew Bresticker wrote: > >> + /* > >> + * TODO: Turn off the clusters when all cores in the cluster > >> + * are down to achieve significant power savings. > >> + */ > > > > This comment should actually be located right after the > > "if (exynos_cluster_unused(cluster))" above. That is where the cluster > > control should be applied, assuming it'll be effective only when WFI is > > executed. > > Correct me if I'm wrong Samsung folks, but I thought it was not > possible to apply cluster power control from a CPU within the cluster > being powered down, i.e. a CPU in the other cluster must be the one to > apply the cluster power control to power down the outbound cluster. Is this true even for deep idle C-states? Nicolas