Messages in this thread | | | Date | Wed, 5 Oct 2011 09:38:09 +0100 | From | Dimitris Papastamos <> | Subject | Re: [PATCH] regcache: Use bsearch() to search the register defaults |
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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 <broonie@opensource.wolfsonmicro.com> > --- > 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 <linux/slab.h> > #include <linux/export.h> > #include <trace/events/regmap.h> > +#include <linux/bsearch.h> > #include <linux/sort.h> > > #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 <dp@opensource.wolfsonmicro.com>
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