Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932275Ab3CPCXJ (ORCPT ); Fri, 15 Mar 2013 22:23:09 -0400 Received: from hqemgate04.nvidia.com ([216.228.121.35]:14417 "EHLO hqemgate04.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754081Ab3CPCXG (ORCPT ); Fri, 15 Mar 2013 22:23:06 -0400 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Fri, 15 Mar 2013 19:22:51 -0700 Message-ID: <1363400599.2879.18.camel@bilhuang-vm1> Subject: Re: [RFC 1/1] clk: Add notifier support in clk_prepare_enable/clk_disable_unprepare From: Bill Huang To: Ulf Hansson CC: Peter De Schrijver , Stephen Warren , Russell King - ARM Linux , "linux-kernel@vger.kernel.org" , "patches@linaro.org" , "linaro-dev@lists.linaro.org" , "linux-arm-kernel@lists.infradead.org" Date: Fri, 15 Mar 2013 19:23:19 -0700 In-Reply-To: References: <1363151317.3311.9.camel@bilhuang-vm1> <51400D9D.9060305@wwwdotorg.org> <1363153204.3311.14.camel@bilhuang-vm1> <5140C12A.4060900@wwwdotorg.org> <1363227311.3311.30.camel@bilhuang-vm1> <20130314092132.GE18519@tbergstrom-lnx.Nvidia.com> <1363253287.3311.32.camel@bilhuang-vm1> <51420EBB.7080503@wwwdotorg.org> <1363310454.3311.44.camel@bilhuang-vm1> <5142B027.4040403@wwwdotorg.org> <20130315093951.GV18519@tbergstrom-lnx.Nvidia.com> <1363349206.5827.10.camel@bilhuang-vm1> X-Mailer: Evolution 3.2.3-0ubuntu6 MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-9" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1358 Lines: 30 On Fri, 2013-03-15 at 20:33 +0800, Ulf Hansson wrote: > I guess you did not fully got what I meant with "dvfs clock type". It > will not affect the clock API. But instead the dvfs is handled by > implementing a specific clk hw type. So the same thing is accomplished > as with clk notifiers, no changes should be needed to device drivers. > > The difference is only that no notifiers will be needed, and all the > dvfs stuff will be handled in the clk hw instead. It will mean that we > will bundle dvfs stuff into the clock drivers, instead of separating > the code outside the clock drivers. But, on the other hand no > notifiers will be needed. > Oh yes I misunderstand your origin point, but my thought is using existing devfreq framework as frequency/voltage policy driver instead of creating another one in clock driver and that's why I think we need the notifier work. By the way, some centralized DVFS implementation like Tegra's VDD_CORE rail has association with tens of clocks which will need to be taken care specially if we're doing those in clock driver I think. > Kind regards > Ulf Hansson -- 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/