From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754382AbaCJT0S (ORCPT ); Mon, 10 Mar 2014 15:26:18 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:39890 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752758AbaCJT0P (ORCPT ); Mon, 10 Mar 2014 15:26:15 -0400 Message-ID: <531E11B7.6080109@ti.com> Date: Mon, 10 Mar 2014 14:25:43 -0500 From: Nishanth Menon User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: Mark Brown , Mike Turquette CC: "Rafael J. Wysocki" , Viresh Kumar , MyungJoo Ham , , , , , , , Subject: Re: [RFC PATCH 3/6] PM / Voltagedomain: introduce voltage domain driver support References: <1392755543-28335-1-git-send-email-nm@ti.com> <1392755543-28335-4-git-send-email-nm@ti.com> <20140224015826.GU25940@sirena.org.uk> <530B594F.2030500@ti.com> <20140303035426.GC2411@sirena.org.uk> <531DF250.5060100@ti.com> <20140310172221.GT28112@sirena.org.uk> <531DF931.1060108@ti.com> <20140310180131.GZ28112@sirena.org.uk> In-Reply-To: <20140310180131.GZ28112@sirena.org.uk> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/10/2014 01:01 PM, Mark Brown wrote: > On Mon, Mar 10, 2014 at 12:41:05PM -0500, Nishanth Menon wrote: > >> The only other options are: >> a) Abstract it at a higher level at "user drivers", since they are >> aware of the sequencing needs - but this partially defeats the >> purpose, unless ofcourse, we do a tricky implementation such as: >> clk a, b, c -> prenotifiers in a, postnotifiers in c (which as you >> mentioned is a little trickier to get right). >> b) introduce a higher level generic dvfs function[1] which does not >> seem very attractive either. > >> Any other suggestions other than limiting the usage(and documenting it >> so) and hoping for a future evolution to take this into consideration? > > Something might be doable with telling the clock API about maintianing > ratios between clocks? I do think we should have an idea where we'd go > with such requirements, even if we don't currently handle it, so that we > can hopefully avoid another round of refactoring everything but it > doesn't seem 100% essential, just very nice to have. > Mike, Any suggestions about the above? could we use composite clocks in some manner here(even though I think the original intent of the same was not the same)? -- Regards, Nishanth Menon