From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932574AbcHWQcQ convert rfc822-to-8bit (ORCPT ); Tue, 23 Aug 2016 12:32:16 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:57640 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932517AbcHWQcN (ORCPT ); Tue, 23 Aug 2016 12:32:13 -0400 Date: Tue, 23 Aug 2016 18:32:06 +0200 From: Sebastian Andrzej Siewior To: Daniel Lezcano Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar , rt@linutronix.de, "Rafael J. Wysocki" , linux-pm@vger.kernel.org Subject: Re: [PATCH 10/16] cpuidle: pseries: Convert to hotplug state machine Message-ID: <20160823163206.xe7dg7ulzj4pzzrs@linutronix.de> References: <20160818125731.27256-1-bigeasy@linutronix.de> <20160818125731.27256-11-bigeasy@linutronix.de> <57BB23CB.2080908@linaro.org> <20160822190404.i56qlimrqkhozacn@linutronix.de> <57BC5AAC.7070707@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: <57BC5AAC.7070707@linaro.org> User-Agent: Mutt/1.6.2-neo (2016-08-08) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016-08-23 16:16:12 [+0200], Daniel Lezcano wrote: > Yes. If we can limit the number of duplicating enum for the same purpose > right now, it would be nice. Okay. > > We could do that but you would have to ensure that only one CPUIDLE > > driver registers itself at a time and for those powerpc drivers it looks > > like you could have two registered (not sure about ARM's little/big (if > > you could have two of those later at run-time)). > > At the first glance, I don't think it is possible to register the cpu > hotplug callback twice because the cpuidle drivers are doing: … > So if a previous driver was already registered, cpuidle_register will > fail and register_cpu_notifier won't be hit. > > There is the same scenario for intel_idle and processor_idle (acpi). I tried to preserve everything as-is during the conversation. However if you are explicitly asking for this and you are sure that it will work then you can get it. No problem :) Sebastian