From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753512AbbFCXhj (ORCPT ); Wed, 3 Jun 2015 19:37:39 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:45070 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751403AbbFCXha (ORCPT ); Wed, 3 Jun 2015 19:37:30 -0400 Date: Wed, 3 Jun 2015 16:37:28 -0700 From: Stephen Boyd To: Boris Brezillon 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: <20150603233728.GA490@codeaurora.org> References: <1432138345-19044-1-git-send-email-boris.brezillon@free-electrons.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1432138345-19044-1-git-send-email-boris.brezillon@free-electrons.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. > @@ -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? -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project