From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from down.free-electrons.com ([37.187.137.238]:54316 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754829AbbGFRPv convert rfc822-to-8bit (ORCPT ); Mon, 6 Jul 2015 13:15:51 -0400 Date: Mon, 6 Jul 2015 19:15:34 +0200 From: Boris Brezillon To: Stephen Boyd Cc: Mike Turquette , linux-clk@vger.kernel.org, Mikko Perttunen , Tomeu Vizoso , Jonathan Corbet , Tony Lindgren , Ralf Baechle , Emilio L??pez , Maxime Ripard , Tero Kristo , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, linux-mips@linux-mips.org Subject: Re: [PATCH v3] clk: change clk_ops' ->determine_rate() prototype Message-ID: <20150706191534.3d0778e0@bbrezillon> In-Reply-To: <20150603233728.GA490@codeaurora.org> References: <1432138345-19044-1-git-send-email-boris.brezillon@free-electrons.com> <20150603233728.GA490@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-clk-owner@vger.kernel.org List-ID: On Wed, 3 Jun 2015 16:37:28 -0700 Stephen Boyd wrote: > On 05/20, Boris Brezillon wrote: > > Clock rates are stored in an unsigned long field, but ->determine_rate() > > (which returns a rounded rate from a requested one) returns a long > > value (errors are reported using negative error codes), which can lead > > to long overflow if the clock rate exceed 2Ghz. > > > > Change ->determine_rate() prototype to return 0 or an error code, and pass > > a pointer to a clk_rate_request structure containing the expected target > > rate and the rate constraints imposed by clk users. > > > > The clk_rate_request structure might be extended in the future to contain > > other kind of constraints like the rounding policy, the maximum clock > > inaccuracy or other things that are not yet supported by the CCF > > (power consumption constraints ?). > > > > Signed-off-by: Boris Brezillon > > > > CC: Jonathan Corbet > > CC: Tony Lindgren > > CC: Ralf Baechle > > CC: "Emilio López" > > CC: Maxime Ripard > > CC: Tero Kristo > > CC: linux-doc@vger.kernel.org > > CC: linux-kernel@vger.kernel.org > > CC: linux-arm-kernel@lists.infradead.org > > CC: linux-omap@vger.kernel.org > > CC: linux-mips@linux-mips.org > > --- > > > > Hi Stephen, > > > > This patch is based on clk-next and contains the changes you suggested > > in your previous review. > > > > It was tested on sama5d4 and compile tested on several ARM platforms > > (those enabled in multi_v7_defconfig). > > > > Thanks. I think we should wait until the next -rc1 drops to apply the > patch for the next merge window. That will make it least likely to conflict > with other trees, and we can provide it on a stable branch should there > be clock providers going through other trees somewhere. Please > remind me if I forget. Just sent a v4 fixing the bug you reported and rebasing my work on 4.2-rc1. > > > @@ -1186,15 +1191,21 @@ EXPORT_SYMBOL_GPL(__clk_determine_rate); > > */ > > unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) > > { > > - unsigned long min_rate; > > - unsigned long max_rate; > > + > > + struct clk_rate_request req; > > + int ret; > > > > if (!clk) > > return 0; > > > > - clk_core_get_boundaries(clk->core, &min_rate, &max_rate); > > + clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate); > > + req.rate = rate; > > + > > + ret = clk_core_round_rate_nolock(clk->core, &req); > > + if (ret) > > + return ret; > > This returns a negative int for unsigned long. Is that intentional? > -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com