From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754618AbdBNTzh (ORCPT ); Tue, 14 Feb 2017 14:55:37 -0500 Received: from mail-vk0-f66.google.com ([209.85.213.66]:33439 "EHLO mail-vk0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754559AbdBNTzW (ORCPT ); Tue, 14 Feb 2017 14:55:22 -0500 MIME-Version: 1.0 In-Reply-To: <20170214194408.GW25384@codeaurora.org> References: <20170128184047.GA24957@dtor-ws> <20170128190309.GN27312@n2100.armlinux.org.uk> <20170128192207.GA38136@dtor-ws> <64ed0890-14f6-42ff-66b1-60f7b3d7d02f@roeck-us.net> <20170128233911.GO27312@n2100.armlinux.org.uk> <20170129180743.GA10917@dtor-ws> <20170130185551.GM8801@codeaurora.org> <20170131005713.GA35974@dtor-ws> <20170207035151.GA18296@dtor-ws> <20170214194408.GW25384@codeaurora.org> From: Dmitry Torokhov Date: Tue, 14 Feb 2017 11:55:20 -0800 Message-ID: Subject: Re: [PATCH v3] clk: add more managed APIs To: Stephen Boyd Cc: Russell King - ARM Linux , Guenter Roeck , Michael Turquette , Viresh Kumar , Andy Shevchenko , linux-clk@vger.kernel.org, lkml Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 14, 2017 at 11:44 AM, Stephen Boyd wrote: > On 02/06, Dmitry Torokhov wrote: >> On Mon, Jan 30, 2017 at 04:57:13PM -0800, Dmitry Torokhov wrote: >> > When converting a driver to managed resources it is desirable to be able to >> > manage all resources in the same fashion. This change allows managing clock >> > prepared and enabled state in the same way we manage many other resources. >> > >> > This adds the following managed APIs: >> > >> > - devm_clk_prepare()/devm_clk_unprepare(); >> > - devm_clk_prepare_enable()/devm_clk_disable_unprepare(). >> > >> > Reviewed-by: Guenter Roeck >> > Signed-off-by: Dmitry Torokhov >> >> It would be awesome if we could get it into 4.11... > > I'd prefer we didn't do this. Instead, make clk_put() drop any > prepare or enables that were done via that clk pointer. Mike > started to do this before[1], but we have some code that assumes > it can do: > > clk = clk_get(...) > clk_prepare_enable(clk) > clk_put(clk) > > and have the clk stay on. Those would need to be changed. That means we'd need to audit entire code base ;( > > We would also need Russell's approval to update the clk_put() > documentation to describe this change in behavior. > > [1] http://lkml.kernel.org/r/1438974570-20812-1-git-send-email-mturquette@baylibre.com > Note that devm* APIs do not preclude from changing clk_put() behavior down the road and it is extremely easy to go and s/devm_clk_prepare_enable/clk_prepare_enable/ once cleanup is automatic. Having devm now will help make driver code better (because right now we either need to add wrappers so devm_add_action_or_reset() can be used, or continue mixing devm* and goto cleanups, which are often wrong). Thanks. -- Dmitry