From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757934Ab1JEIiR (ORCPT ); Wed, 5 Oct 2011 04:38:17 -0400 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:50042 "EHLO opensource.wolfsonmicro.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752658Ab1JEIiN (ORCPT ); Wed, 5 Oct 2011 04:38:13 -0400 Date: Wed, 5 Oct 2011 09:38:09 +0100 From: Dimitris Papastamos To: Mark Brown Cc: patches@opensource.wolfsonmicro.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] regcache: Use bsearch() to search the register defaults Message-ID: <20111005083809.GA16418@opensource.wolfsonmicro.com> References: <1317762396-1248-1-git-send-email-broonie@opensource.wolfsonmicro.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1317762396-1248-1-git-send-email-broonie@opensource.wolfsonmicro.com> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 04, 2011 at 10:06:36PM +0100, Mark Brown wrote: > Rather than open coding a binary search use the standard bsearch() using > the comparison function we're already using for sort() on insert. This > fixes a lockup I was observing due to iterating on min <= max rather > than min < max when we fail to look up. > > Signed-off-by: Mark Brown > --- > drivers/base/regmap/regcache.c | 40 ++++++++++++++++++++-------------------- > 1 files changed, 20 insertions(+), 20 deletions(-) > > diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c > index 18ab5b3..bf82783 100644 > --- a/drivers/base/regmap/regcache.c > +++ b/drivers/base/regmap/regcache.c > @@ -13,6 +13,7 @@ > #include > #include > #include > +#include > #include > > #include "internal.h" > @@ -356,25 +357,7 @@ unsigned int regcache_get_val(const void *base, unsigned int idx, > return -1; > } > > -int regcache_lookup_reg(struct regmap *map, unsigned int reg) > -{ > - unsigned int min, max, index; > - > - min = 0; > - max = map->num_reg_defaults - 1; > - do { > - index = (min + max) / 2; > - if (map->reg_defaults[index].reg == reg) > - return index; > - if (map->reg_defaults[index].reg < reg) > - min = index + 1; > - else > - max = index; > - } while (min <= max); > - return -1; > -} > - > -static int regcache_insert_cmp(const void *a, const void *b) > +static int regcache_default_cmp(const void *a, const void *b) > { > const struct reg_default *_a = a; > const struct reg_default *_b = b; > @@ -382,6 +365,23 @@ static int regcache_insert_cmp(const void *a, const void *b) > return _a->reg - _b->reg; > } > > +int regcache_lookup_reg(struct regmap *map, unsigned int reg) > +{ > + struct reg_default key; > + struct reg_default *r; > + > + key.reg = reg; > + key.def = 0; > + > + r = bsearch(&key, map->reg_defaults, map->num_reg_defaults, > + sizeof(struct reg_default), regcache_default_cmp); > + > + if (r) > + return r - map->reg_defaults; > + else > + return -1; > +} > + > int regcache_insert_reg(struct regmap *map, unsigned int reg, > unsigned int val) > { > @@ -397,6 +397,6 @@ int regcache_insert_reg(struct regmap *map, unsigned int reg, > map->reg_defaults[map->num_reg_defaults - 1].reg = reg; > map->reg_defaults[map->num_reg_defaults - 1].def = val; > sort(map->reg_defaults, map->num_reg_defaults, > - sizeof(struct reg_default), regcache_insert_cmp, NULL); > + sizeof(struct reg_default), regcache_default_cmp, NULL); > return 0; > } > -- > 1.7.6.3 > Looks good :) Acked-by: Dimitris Papastamos