regmap: Use bsearch() to search the register defaults

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>
Acked-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index b10e38fa0e3f44e4535bafd599dc7aedfaf28849..c5379c86de883b0239aa0613aefe99964b1a7fc5 100644 (file)
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -12,6 +12,7 @@
 
 #include <linux/slab.h>
 #include <trace/events/regmap.h>
+#include <linux/bsearch.h>
 #include <linux/sort.h>
 
 #include "internal.h"
@@ -355,25 +356,7 @@ 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;
@@ -381,6 +364,23 @@ 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)
 {
@@ -396,6 +396,6 @@ 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;
 }