From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753166AbbCaJdK (ORCPT ); Tue, 31 Mar 2015 05:33:10 -0400 Received: from mga01.intel.com ([192.55.52.88]:17005 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751155AbbCaJdG (ORCPT ); Tue, 31 Mar 2015 05:33:06 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.11,499,1422950400"; d="scan'208";a="706623326" Message-ID: <1427794383.14897.453.camel@linux.intel.com> Subject: Re: [PATCH v2 1/2] clk: fractional-divider: switch to rational best approximation From: Andy Shevchenko To: Andy Shevchenko Cc: Stephen Boyd , "linux-kernel@vger.kernel.org" , "Krogerus, Heikki" Date: Tue, 31 Mar 2015 12:33:03 +0300 In-Reply-To: References: <1427741869-239562-1-git-send-email-andriy.shevchenko@linux.intel.com> <1427741869-239562-2-git-send-email-andriy.shevchenko@linux.intel.com> <5519EB1D.6070200@codeaurora.org> Organization: Intel Finland Oy Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.9-1+b1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2015-03-31 at 10:42 +0300, Andy Shevchenko wrote: > On Tue, Mar 31, 2015 at 3:32 AM, Stephen Boyd wrote: > > On 03/30/15 11:57, Andy Shevchenko wrote: > >> This patch converts the code to use rational best approximation algorithm which > >> is more precise. > > >> --- a/drivers/clk/Kconfig > >> +++ b/drivers/clk/Kconfig > >> @@ -14,6 +14,7 @@ config COMMON_CLK > >> select HAVE_CLK_PREPARE > >> select CLKDEV_LOOKUP > >> select SRCU > >> + select RATIONAL > >> ---help--- > >> The common clock framework is a single definition of struct > >> clk, useful across many platforms, as well as an > >> @@ -63,7 +64,6 @@ config COMMON_CLK_SI5351 > >> tristate "Clock driver for SiLabs 5351A/B/C" > >> depends on I2C > >> select REGMAP_I2C > >> - select RATIONAL > >> ---help--- > >> This driver supports Silicon Labs 5351A/B/C programmable clock > >> generators. > >> @@ -139,7 +139,6 @@ config COMMON_CLK_CDCE706 > >> tristate "Clock driver for TI CDCE706 clock synthesizer" > >> depends on I2C > >> select REGMAP_I2C > >> - select RATIONAL > >> ---help--- > >> This driver supports TI CDCE706 programmable 3-PLL clock synthesizer. > > > > Will some kernel janitor find us if we leave the selects here? I know > > you removed it because COMMON_CLK must be Y here and we'd always select > > RATIONAL, but it feels better to leave it alone and actually split off > > the basic clock types into individual configs so that the tiny kernel > > users don't have unused code lying around. That could be future work > > someday and then we might forget to select RATIONAL again. > > I'm fine with that as well. So, do I need to resend or you apply > modified version? There are couple of issues with arithmetics, such as we can't use mult_frac() because of potential overflow on 32 bit kernels, so I will resend new version. -- Andy Shevchenko Intel Finland Oy