From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH 2/2] ARM: OMAP2+: fix dpll round_rate() to actually round Date: Thu, 13 Feb 2014 15:00:11 -0800 Message-ID: <20140213230011.GH28216@atomide.com> References: <1389944699-27962-1-git-send-email-tomi.valkeinen@ti.com> <1389944699-27962-3-git-send-email-tomi.valkeinen@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-03-ewr.mailhop.org ([204.13.248.66]:55438 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750932AbaBMXAY (ORCPT ); Thu, 13 Feb 2014 18:00:24 -0500 Content-Disposition: inline In-Reply-To: <1389944699-27962-3-git-send-email-tomi.valkeinen@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tomi Valkeinen Cc: Tero Kristo , linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, Mike Turquette , Paul Walmsley * Tomi Valkeinen [140116 23:47]: > omap2_dpll_round_rate() doesn't actually round the given rate, even if > the name and the description so hints. Instead it only tries to find an > exact rate match, or if that fails, return ~0 as an error. > > What this basically means is that the user of the clock needs to know > what rates the dpll can support, which obviously isn't right. > > This patch adds a simple method of rounding: during the iteration, the > code keeps track of the closest rate match. If no exact match is found, > the closest is returned. > > Signed-off-by: Tomi Valkeinen Paul & Tero, please ack if you want me to queue this. Tony > --- > arch/arm/mach-omap2/clkt_dpll.c | 17 ++++++++++++----- > 1 file changed, 12 insertions(+), 5 deletions(-) > > diff --git a/arch/arm/mach-omap2/clkt_dpll.c b/arch/arm/mach-omap2/clkt_dpll.c > index 1f1708ef77bb..1b4e68dfb713 100644 > --- a/arch/arm/mach-omap2/clkt_dpll.c > +++ b/arch/arm/mach-omap2/clkt_dpll.c > @@ -298,6 +298,7 @@ long omap2_dpll_round_rate(struct clk_hw *hw, unsigned long target_rate, > struct dpll_data *dd; > unsigned long ref_rate; > const char *clk_name; > + unsigned long diff, closest_diff = ~0; > > if (!clk || !clk->dpll_data) > return ~0; > @@ -345,20 +346,26 @@ long omap2_dpll_round_rate(struct clk_hw *hw, unsigned long target_rate, > pr_debug("clock: %s: m = %d: n = %d: new_rate = %lu\n", > clk_name, m, n, new_rate); > > - if (target_rate == new_rate) { > + diff = max(target_rate, new_rate) - min(target_rate, new_rate); > + > + if (diff < closest_diff) { > + closest_diff = diff; > + > dd->last_rounded_m = m; > dd->last_rounded_n = n; > - dd->last_rounded_rate = target_rate; > - break; > + dd->last_rounded_rate = new_rate; > + > + if (diff == 0) > + break; > } > } > > - if (target_rate != new_rate) { > + if (closest_diff == ~0) { > pr_debug("clock: %s: cannot round to rate %lu\n", > clk_name, target_rate); > return ~0; > } > > - return target_rate; > + return dd->last_rounded_rate; > } > > -- > 1.8.3.2 > From mboxrd@z Thu Jan 1 00:00:00 1970 From: tony@atomide.com (Tony Lindgren) Date: Thu, 13 Feb 2014 15:00:11 -0800 Subject: [PATCH 2/2] ARM: OMAP2+: fix dpll round_rate() to actually round In-Reply-To: <1389944699-27962-3-git-send-email-tomi.valkeinen@ti.com> References: <1389944699-27962-1-git-send-email-tomi.valkeinen@ti.com> <1389944699-27962-3-git-send-email-tomi.valkeinen@ti.com> Message-ID: <20140213230011.GH28216@atomide.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org * Tomi Valkeinen [140116 23:47]: > omap2_dpll_round_rate() doesn't actually round the given rate, even if > the name and the description so hints. Instead it only tries to find an > exact rate match, or if that fails, return ~0 as an error. > > What this basically means is that the user of the clock needs to know > what rates the dpll can support, which obviously isn't right. > > This patch adds a simple method of rounding: during the iteration, the > code keeps track of the closest rate match. If no exact match is found, > the closest is returned. > > Signed-off-by: Tomi Valkeinen Paul & Tero, please ack if you want me to queue this. Tony > --- > arch/arm/mach-omap2/clkt_dpll.c | 17 ++++++++++++----- > 1 file changed, 12 insertions(+), 5 deletions(-) > > diff --git a/arch/arm/mach-omap2/clkt_dpll.c b/arch/arm/mach-omap2/clkt_dpll.c > index 1f1708ef77bb..1b4e68dfb713 100644 > --- a/arch/arm/mach-omap2/clkt_dpll.c > +++ b/arch/arm/mach-omap2/clkt_dpll.c > @@ -298,6 +298,7 @@ long omap2_dpll_round_rate(struct clk_hw *hw, unsigned long target_rate, > struct dpll_data *dd; > unsigned long ref_rate; > const char *clk_name; > + unsigned long diff, closest_diff = ~0; > > if (!clk || !clk->dpll_data) > return ~0; > @@ -345,20 +346,26 @@ long omap2_dpll_round_rate(struct clk_hw *hw, unsigned long target_rate, > pr_debug("clock: %s: m = %d: n = %d: new_rate = %lu\n", > clk_name, m, n, new_rate); > > - if (target_rate == new_rate) { > + diff = max(target_rate, new_rate) - min(target_rate, new_rate); > + > + if (diff < closest_diff) { > + closest_diff = diff; > + > dd->last_rounded_m = m; > dd->last_rounded_n = n; > - dd->last_rounded_rate = target_rate; > - break; > + dd->last_rounded_rate = new_rate; > + > + if (diff == 0) > + break; > } > } > > - if (target_rate != new_rate) { > + if (closest_diff == ~0) { > pr_debug("clock: %s: cannot round to rate %lu\n", > clk_name, target_rate); > return ~0; > } > > - return target_rate; > + return dd->last_rounded_rate; > } > > -- > 1.8.3.2 >