From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 0/3] cpufreq: dt: Create platform device from generic code Date: Tue, 29 Mar 2016 15:22:59 +0200 Message-ID: <4279257.XRWOdgISPj@wuerfel> References: <4531000.a0G78BGFu1@wuerfel> <20160325044124.GN22062@vireshk-i7> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from mout.kundenserver.de ([212.227.17.13]:54160 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751584AbcC2NX2 (ORCPT ); Tue, 29 Mar 2016 09:23:28 -0400 In-Reply-To: <20160325044124.GN22062@vireshk-i7> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Viresh Kumar Cc: linaro-kernel@lists.linaro.org, Rafael Wysocki , arnd.bergmann@linaro.org, kgene.kim@samsung.com, heiko@sntech.de, xf@rock-chips.com, mmcclint@codeaurora.org, linux-pm@vger.kernel.org On Friday 25 March 2016 10:11:24 Viresh Kumar wrote: > On 24-03-16, 15:16, Arnd Bergmann wrote: > > Hmm, can you give an example where this is needed? > > I don't remember them, but I am quite sure that I have seen people > asking for that support again and again. > > > I assume you are > > thinking of some clock controller or regulator that gets initialized > > after the cpufreq driver, right? > > Yeah. > > > Are there any that are in loadable modules, rather than just later > > in the init sequence for built-in drivers? > > Maybe both, don't remember. Sorry. > > Over that, independent of what the users are doing today, I think its > important to support defer probing for anyone that wants to use it. Ok. > > I think we do care about compatibility there, but there are clearly > > other ways to handle the special case for opp-v1 if we want to. > > Okay, and what are those ? There is only one platform which has used > the pdata, mvebu. The platform already calls dev_pm_opp_add(), so it directly interacts with the cpufreq infrastructure. One way to do it would be to add another function call to set the independent_clocks flag in a static variable owned by that. Another way would be to have a separate function call for doing dev_pm_opp_add() with independent clocks. As far as I can tell, the two (dev_pm_opp_add and independent_clocks) are already tightly coupled interfaces, so it makes sense to combine them. Arnd