From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756018AbbA1UV1 (ORCPT ); Wed, 28 Jan 2015 15:21:27 -0500 Received: from e33.co.us.ibm.com ([32.97.110.151]:49981 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754585AbbA1UVY (ORCPT ); Wed, 28 Jan 2015 15:21:24 -0500 Message-ID: <54C8B0E6.5080406@linux.vnet.ibm.com> Date: Wed, 28 Jan 2015 15:20:30 +0530 From: Preeti U Murthy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Stewart Smith , mpe@ellerman.id.au CC: rafael.j.wysocki@intel.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH V2] cpuidle/powernv: Read target_residency value of idle states from DT if available References: <20150128021044.11166.81418.stgit@preeti.in.ibm.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15012809-0009-0000-0000-000008515FE6 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/28/2015 02:45 PM, Stewart Smith wrote: > Preeti U Murthy writes: >> The device tree now exposes the residency values for different idle states. Read >> these values instead of calculating residency from the latency values. The values >> exposed in the DT are validated for optimal power efficiency. However to maintain >> compatibility with the older firmware code which does not expose residency >> values, use default values as a fallback mechanism. While at it, handle some >> cleanups. > > From a "I just merged the patch that exports these values from firmware" > point of view, using them and falling back looks good. > > (I find the hardcoding of snooze in the driver a bit odd, as is the Snooze is the only software defined idle state, the rest are platform specific. The first idle state is usually associated with some sort of a polling operation and each architecture has a variant to this. This is why we end up hard-coding this idle state in the driver as far as my understanding goes. > hardcoding of max power states to 8 - which could bite us in the future Hmm.. not sure about this. Need to check. > if a future processor has more states... but these aren't problems with > this patch) > > Acked-by: Stewart Smith Thanks! Regards Preeti U Murthy >