[PATCH] drivers: regmap: bugfix in regcache-rbtree.c

David Jander
2013-08-21T13:24:51Z

The functionality of rbtree_ctx->cached_rbnode is broken. Remove it to
avoid hitting the wrong rbnode when locating a register.
rbnode register ranges can overlap, which is not a problem as long as
every lookup for a register returns the same rbnode. Therefor we need
to start searching from the top of the rb-tree _always_.

Signed-off-by: David Jander <david@protonic.nl>
---
drivers/base/regmap/regcache-rbtree.c | 13 -------------
1 file changed, 13 deletions(-)

diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
index 5c1435c..2f9783f 100644
--- a/drivers/base/regmap/regcache-rbtree.c
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -35,7 +35,6 @@ struct regcache_rbtree_node {

struct regcache_rbtree_ctx {
struct rb_root root;
- struct regcache_rbtree_node *cached_rbnode;
};

static inline void regcache_rbtree_get_base_top_reg(
@@ -68,21 +67,12 @@ static struct regcache_rbtree_node *regcache_rbtree_lookup(struct regmap *map,
struct regcache_rbtree_node *rbnode;
unsigned int base_reg, top_reg;

- rbnode = rbtree_ctx->cached_rbnode;
- if (rbnode) {
- regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
- &top_reg);
- if (reg >= base_reg && reg <= top_reg)
- return rbnode;
- }
-
node = rbtree_ctx->root.rb_node;
while (node) {
rbnode = container_of(node, struct regcache_rbtree_node, node);
regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
&top_reg);
if (reg >= base_reg && reg <= top_reg) {
- rbtree_ctx->cached_rbnode = rbnode;
return rbnode;
} else if (reg > top_reg) {
node = node->rb_right;
@@ -209,7 +199,6 @@ static int regcache_rbtree_init(struct regmap *map)

rbtree_ctx = map->cache;
rbtree_ctx->root = RB_ROOT;
- rbtree_ctx->cached_rbnode = NULL;

for (i = 0; i < map->num_reg_defaults; i++) {
ret = regcache_rbtree_write(map,
@@ -392,7 +381,6 @@ static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
value);
if (ret)
return ret;
- rbtree_ctx->cached_rbnode = rbnode_tmp;
return 0;
}
}
@@ -406,7 +394,6 @@ static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
regcache_rbtree_set_register(map, rbnode,
reg - rbnode->base_reg, value);
regcache_rbtree_insert(map, &rbtree_ctx->root, rbnode);
- rbtree_ctx->cached_rbnode = rbnode;
}

return 0;
--
1.8.1.2