From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753653Ab2KGOx5 (ORCPT ); Wed, 7 Nov 2012 09:53:57 -0500 Received: from comal.ext.ti.com ([198.47.26.152]:48132 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751762Ab2KGOxz (ORCPT ); Wed, 7 Nov 2012 09:53:55 -0500 Date: Wed, 7 Nov 2012 08:53:52 -0600 From: Nishanth Menon To: Joshua Emele CC: Kevin Hilman , "Rafael J. Wysocki" , , , , Subject: Re: [PATCH 1/4] cpufreq: OMAP: if an iva clock name is specified, load iva resources Message-ID: <20121107145352.GA15742@kahuna> References: <1352252861-18384-1-git-send-email-jemele@gmail.com> <1352252861-18384-2-git-send-email-jemele@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1352252861-18384-2-git-send-email-jemele@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17:47-20121106, Joshua Emele wrote: > +static int __cpuinit omap_iva_init(struct cpufreq_policy *policy) > +{ > + int result; > + if (!iva_clk_name) { > + pr_info("%s: iva unavailable\n", __func__); > + return 0; > + } > + iva_dev = omap_device_get_by_hwmod_name("iva"); NAK. Reasons as follows: a) cpufreq is purely meant for cpu, not IVA. we should instead be using devfreq which is designed around the usage for co-processor b) clubbing ARM's frequency decision is definitely NOT equal to IVA frequency decision, not only is it wrong in terms of modularization, it is wrong in terms of power benefits as well (not to mention weirdness needed when you look at all OMAP SoC variants) c) DVFS is not trivial around multiple co-processor transitions -> core OPPs (as dependent OPP) needs to be addressed as well. ideally common clock framework could take care of clock dependencies. -- Regards, Nishanth Menon