From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751348AbdEaReH (ORCPT ); Wed, 31 May 2017 13:34:07 -0400 Received: from foss.arm.com ([217.140.101.70]:47372 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750998AbdEaReF (ORCPT ); Wed, 31 May 2017 13:34:05 -0400 Cc: Sudeep Holla , rjw@rjwysocki.net, lorenzo.pieralisi@arm.com, leo.yan@linaro.org, "open list:CPUIDLE DRIVERS" , open list Subject: Re: [PATCH] ARM: cpuidle: Support asymmetric idle definition To: Daniel Lezcano References: <1495212343-24873-1-git-send-email-daniel.lezcano@linaro.org> <850fab54-d6e6-7b4c-631a-f4ee658c96fa@arm.com> <45754d0a-6a98-2987-74ed-429926d89cbc@arm.com> <3ce7048e-6d9d-9e46-a6fb-4d3263231536@arm.com> <8c5b46d1-8b34-2ced-e27d-4d76f80953c6@arm.com> <77df6298-945b-7663-0cb9-cd24fa583c6a@linaro.org> From: Sudeep Holla Organization: ARM Message-ID: <160c3091-2d10-9c7b-c55b-e76abf23653f@arm.com> Date: Wed, 31 May 2017 18:33:52 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <77df6298-945b-7663-0cb9-cd24fa583c6a@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 31/05/17 17:40, Daniel Lezcano wrote: > Hi Sudeep, Lorenzo, > > I have been thinking and looking at the domain-idle-state and I don't > see an obvious connection between what is describing the power domain, > the cpu idle driver and what we are trying to achieve. > I am not sure what you mean by *connection* above. 1. With old flat list of idle states, we should get the cpumask sharing the idle states from the phandle or something similar. 2. With new domain-idle-state and hierarchical DT binding, you just need to infer that from the hierarchy. > I would like to suggest something much more simple, register a cpuidle > driver per cpu, so every cpu can have its own idle definitions, that > should work for dynamiQ, smp and hmp. The impact on the driver will be > minimal. > Sounds simple, but not sure if it's scalable on platforms with relatively large number of CPUs like 48 or 96(e.g. Cavium Thunder -- Regards, Sudeep