Merge tag 'regmap-fix-v6.7-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap fix from Mark Brown:
 "One fix here, for an interaction between noinc registers and caches.

  If a device uses noinc registers (which is rare) then we could corrupt
  registers after the noinc register in the cache"

* tag 'regmap-fix-v6.7-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: prevent noinc writes from clobbering cache

1 files changed, 9 insertions, 7 deletions

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 234a84ecde8b1b..ea615774719941 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1620,17 +1620,19 @@ static int _regmap_raw_write_impl(struct regmap *map, unsigned int reg,
 	}
 
 	if (!map->cache_bypass && map->format.parse_val) {
-		unsigned int ival;
+		unsigned int ival, offset;
 		int val_bytes = map->format.val_bytes;
-		for (i = 0; i < val_len / val_bytes; i++) {
-			ival = map->format.parse_val(val + (i * val_bytes));
-			ret = regcache_write(map,
-					     reg + regmap_get_offset(map, i),
-					     ival);
+
+		/* Cache the last written value for noinc writes */
+		i = noinc ? val_len - val_bytes : 0;
+		for (; i < val_len; i += val_bytes) {
+			ival = map->format.parse_val(val + i);
+			offset = noinc ? 0 : regmap_get_offset(map, i / val_bytes);
+			ret = regcache_write(map, reg + offset, ival);
 			if (ret) {
 				dev_err(map->dev,
 					"Error in caching of register: %x ret: %d\n",
-					reg + regmap_get_offset(map, i), ret);
+					reg + offset, ret);
 				return ret;
 			}
 		}