From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751369AbdFAHh4 (ORCPT ); Thu, 1 Jun 2017 03:37:56 -0400 Received: from mail-wm0-f44.google.com ([74.125.82.44]:34804 "EHLO mail-wm0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751090AbdFAHhy (ORCPT ); Thu, 1 Jun 2017 03:37:54 -0400 Subject: Re: [PATCH] ARM: cpuidle: Support asymmetric idle definition To: Sudeep Holla Cc: rjw@rjwysocki.net, lorenzo.pieralisi@arm.com, leo.yan@linaro.org, "open list:CPUIDLE DRIVERS" , open list 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> <160c3091-2d10-9c7b-c55b-e76abf23653f@arm.com> From: Daniel Lezcano Message-ID: <77a67a7d-4a0d-29b7-dee3-1584f2134309@linaro.org> Date: Thu, 1 Jun 2017 09:37:50 +0200 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: <160c3091-2d10-9c7b-c55b-e76abf23653f@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 31/05/2017 19:33, Sudeep Holla wrote: > > > 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 I'm pretty sure it scales, we had the idle states per cpuidle devices and nobody was complaining. But I agree it could be optimized. -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog