Merge remote-tracking branch 'regmap/fix/rbtree' into regmap-linus

diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
index aa56af87d94118338befbbf62aa7f7b64cfd6570..b11af3f2c1dbf2e1d6faf31cb7bc38e663b2285c 100644 (file)
--- a/drivers/base/regmap/regcache-rbtree.c
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -404,6 +404,7 @@ static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
                unsigned int new_base_reg, new_top_reg;
                unsigned int min, max;
                unsigned int max_dist;
+               unsigned int dist, best_dist = UINT_MAX;
 
                max_dist = map->reg_stride * sizeof(*rbnode_tmp) /
                        map->cache_word_size;
@@ -423,24 +424,41 @@ static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
                                &base_reg, &top_reg);
 
                        if (base_reg <= max && top_reg >= min) {
-                               new_base_reg = min(reg, base_reg);
-                               new_top_reg = max(reg, top_reg);
-                       } else {
-                               if (max < base_reg)
-                                       node = node->rb_left;
+                               if (reg < base_reg)
+                                       dist = base_reg - reg;
+                               else if (reg > top_reg)
+                                       dist = reg - top_reg;
                                else
-                                       node = node->rb_right;
-
-                               continue;
+                                       dist = 0;
+                               if (dist < best_dist) {
+                                       rbnode = rbnode_tmp;
+                                       best_dist = dist;
+                                       new_base_reg = min(reg, base_reg);
+                                       new_top_reg = max(reg, top_reg);
+                               }
                        }
 
-                       ret = regcache_rbtree_insert_to_block(map, rbnode_tmp,
+                       /*
+                        * Keep looking, we want to choose the closest block,
+                        * otherwise we might end up creating overlapping
+                        * blocks, which breaks the rbtree.
+                        */
+                       if (reg < base_reg)
+                               node = node->rb_left;
+                       else if (reg > top_reg)
+                               node = node->rb_right;
+                       else
+                               break;
+               }
+
+               if (rbnode) {
+                       ret = regcache_rbtree_insert_to_block(map, rbnode,
                                                              new_base_reg,
                                                              new_top_reg, reg,
                                                              value);
                        if (ret)
                                return ret;
-                       rbtree_ctx->cached_rbnode = rbnode_tmp;
+                       rbtree_ctx->cached_rbnode = rbnode;
                        return 0;
                }