Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754557Ab3GPJf3 (ORCPT ); Tue, 16 Jul 2013 05:35:29 -0400 Received: from mail-oa0-f52.google.com ([209.85.219.52]:64114 "EHLO mail-oa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753928Ab3GPJf1 (ORCPT ); Tue, 16 Jul 2013 05:35:27 -0400 MIME-Version: 1.0 In-Reply-To: <51E51276.9020805@linux.vnet.ibm.com> References: <20130711221419.547.69781.stgit@srivatsabhat.in.ibm.com> <20130711221704.547.64296.stgit@srivatsabhat.in.ibm.com> <51E3C950.90503@linux.vnet.ibm.com> <51E50AD4.6040208@linux.vnet.ibm.com> <51E51276.9020805@linux.vnet.ibm.com> Date: Tue, 16 Jul 2013 15:05:26 +0530 Message-ID: Subject: Re: [PATCH 7/8] cpufreq: Preserve policy structure across suspend/resume From: Viresh Kumar To: "Srivatsa S. Bhat" Cc: rjw@sisk.pl, toralf.foerster@gmx.de, robert.jarzmik@intel.com, durgadoss.r@intel.com, tianyu.lan@intel.com, lantianyu1986@gmail.com, dirk.brandewie@gmail.com, stern@rowland.harvard.edu, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1644 Lines: 35 On 16 July 2013 14:59, Srivatsa S. Bhat wrote: > On 07/16/2013 02:40 PM, Viresh Kumar wrote: >> So, even if you don't keep the fallback storage, things should work >> without any issue (probably worth trying as this will get rid of a per >> cpu variable :)) >> > > No, I already tried that and it didn't work ;-( The thing is, we need the > __cpufreq_add_dev() code to call the ->init() routines of drivers etc. But if > it finds the policy structure, it will skip all of that initialization and happily > proceed. Which is precisely the cause of all the erratic behaviour we are seeing > (ie., lack of proper initialization post-resume). I missed that point. :) > So this approach keeps the memory preserved in a fallback storage and lets the > init code run to full completion without any issues. > > Perhaps we could do some _more_ code reorganization in the future to take this > issue into account etc., but IMHO that might be non-trivial. I'm trying to keep > this as simple and straight-forward as possible as a first step, to atleast get > it properly working. (Changing the order in which init is done is kinda scary > since its hard to comprehend what assumptions we might be breaking!). > > We can perhaps revisit your idea later and optimize out the extra per-cpu data. No, we don't need to optimize it that way. Current design looks good for now. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/