From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933487AbdDGLpP (ORCPT ); Fri, 7 Apr 2017 07:45:15 -0400 Received: from hqemgate16.nvidia.com ([216.228.121.65]:10322 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932939AbdDGLpG (ORCPT ); Fri, 7 Apr 2017 07:45:06 -0400 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Fri, 07 Apr 2017 04:45:06 -0700 Date: Fri, 7 Apr 2017 14:44:40 +0300 From: Peter De Schrijver To: Michael Turquette , Stephen Boyd , , Subject: Re: [PATCH] clk: Re-evaluate clock rate on min/max update Message-ID: <20170407114440.GD25177@tbergstrom-lnx.Nvidia.com> References: <1490103807-21821-1-git-send-email-pdeschrijver@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1490103807-21821-1-git-send-email-pdeschrijver@nvidia.com> X-NVConfidentiality: public User-Agent: Mutt/1.5.21 (2010-09-15) X-Originating-IP: [10.21.24.170] X-ClientProxiedBy: UKMAIL102.nvidia.com (10.26.138.15) To UKMAIL101.nvidia.com (10.26.138.13) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 21, 2017 at 03:43:26PM +0200, Peter De Schrijver wrote: > Whenever a user change its min or max rate limit of a clock, we need to > re-evaluate the current clock rate and possibly change it if the new limits > require so. To do this clk_set_rate_range() already calls > clk_core_set_rate_nolock, however this won't have the intended effect > because the core clock rate hasn't changed. To fix this, move the test to > avoid setting the same core clock rate again, to clk_set_rate() so > clk_core_set_rate_nolock() can change the clock rate when min or max have > been updated, even when the core clock rate has not changed. > Ping! Any comments on this? Peter. > Signed-off-by: Peter De Schrijver > --- > drivers/clk/clk.c | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index 2fa2fb8..0b815d1 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -1569,10 +1569,6 @@ static int clk_core_set_rate_nolock(struct clk_core *core, > if (!core) > return 0; > > - /* bail early if nothing to do */ > - if (rate == clk_core_get_rate_nolock(core)) > - return 0; > - > if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count) > return -EBUSY; > > @@ -1621,16 +1617,21 @@ static int clk_core_set_rate_nolock(struct clk_core *core, > */ > int clk_set_rate(struct clk *clk, unsigned long rate) > { > - int ret; > + int ret = 0; > > if (!clk) > - return 0; > + return ret; > > /* prevent racing with updates to the clock topology */ > clk_prepare_lock(); > > + /* bail early if nothing to do */ > + if (rate == clk_core_get_rate_nolock(clk->core)) > + goto out; > + > ret = clk_core_set_rate_nolock(clk->core, rate); > > +out: > clk_prepare_unlock(); > > return ret; > -- > 1.9.1 >