regmap: cache Fix regcache-rbtree sync

commit 8abac3ba51b5525354e9b2ec0eed1c9e95c905d9 upstream.

The last register block, which falls into the specified range, is not handled
correctly. The formula which calculates the number of register which should be
synced is inverse (and off by one). E.g. if all registers in that block should
be synced only one is synced, and if only one should be synced all (but one) are
synced. To calculate the number of registers that need to be synced we need to
subtract the number of the first register in the block from the max register
number and add one. This patch updates the code accordingly.

The issue was introduced in commit ac8d91c ("regmap: Supply ranges to the sync
operations").

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
index 92b779ee002bba20b6af60953aa2132526380c4e..17aa318a1aeaf4ab5ed4332a8e9fe52c9c862206 100644 (file)
--- a/drivers/base/regmap/regcache-rbtree.c
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -392,7 +392,7 @@ static int regcache_rbtree_sync(struct regmap *map, unsigned int min,
                        base = 0;
 
                if (max < rbnode->base_reg + rbnode->blklen)
-                       end = rbnode->base_reg + rbnode->blklen - max;
+                       end = max - rbnode->base_reg + 1;
                else
                        end = rbnode->blklen;