regcache: Make sure we sync register 0 in an rbtree cache

Most of the current users have register 0 as a volatile register or don't
have a register 0 so it's not been apparent that it's not getting synced.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
index 32620c4f168..861ad2c81df 100644
--- a/drivers/base/regmap/regcache-rbtree.c
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -377,7 +377,7 @@ static int regcache_rbtree_sync(struct regmap *map)
 
                         /* Is this the hardware default?  If so skip. */
                         ret = regcache_lookup_reg(map, i);
-                        if (ret > 0 && val == map->reg_defaults[ret].def)
+                        if (ret >= 0 && val == map->reg_defaults[ret].def)
                                 continue;
 
                         map->cache_bypass = 1;