2 files changed, 23 insertions, 8 deletions

diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
index 81751a49d8bf..56486d92c4e7 100644
--- a/drivers/base/regmap/regcache-rbtree.c
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -296,11 +296,20 @@ static int regcache_rbtree_insert_to_block(struct regmap *map,
 	if (!blk)
 		return -ENOMEM;
 
-	present = krealloc(rbnode->cache_present,
-		    BITS_TO_LONGS(blklen) * sizeof(*present), GFP_KERNEL);
-	if (!present) {
-		kfree(blk);
-		return -ENOMEM;
+	if (BITS_TO_LONGS(blklen) > BITS_TO_LONGS(rbnode->blklen)) {
+		present = krealloc(rbnode->cache_present,
+				   BITS_TO_LONGS(blklen) * sizeof(*present),
+				   GFP_KERNEL);
+		if (!present) {
+			kfree(blk);
+			return -ENOMEM;
+		}
+
+		memset(present + BITS_TO_LONGS(rbnode->blklen), 0,
+		       (BITS_TO_LONGS(blklen) - BITS_TO_LONGS(rbnode->blklen))
+		       * sizeof(*present));
+	} else {
+		present = rbnode->cache_present;
 	}
 
 	/* insert the register value in the correct place in the rbnode block */
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 27456c7978b9..a6b6f7ee87ee 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1386,7 +1386,8 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg,
  */
 bool regmap_can_raw_write(struct regmap *map)
 {
-	return map->bus && map->format.format_val && map->format.format_reg;
+	return map->bus && map->bus->write && map->format.format_val &&
+		map->format.format_reg;
 }
 EXPORT_SYMBOL_GPL(regmap_can_raw_write);
 
@@ -1761,7 +1762,7 @@ EXPORT_SYMBOL_GPL(regmap_bulk_write);
  *
  * the (register,newvalue) pairs in regs have not been formatted, but
  * they are all in the same page and have been changed to being page
- * relative. The page register has been written if that was neccessary.
+ * relative. The page register has been written if that was necessary.
  */
 static int _regmap_raw_multi_reg_write(struct regmap *map,
 				       const struct reg_default *regs,
@@ -2071,7 +2072,7 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 
 	/*
 	 * Some buses or devices flag reads by setting the high bits in the
-	 * register addresss; since it's always the high bits for all
+	 * register address; since it's always the high bits for all
 	 * current formats we can do this here rather than in
 	 * formatting.  This may break if we get interesting formats.
 	 */
@@ -2205,6 +2206,11 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 
 	if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
 	    map->cache_type == REGCACHE_NONE) {
+		if (!map->bus->read) {
+			ret = -ENOTSUPP;
+			goto out;
+		}
+
 		/* Physical block read if there's no cache involved */
 		ret = _regmap_raw_read(map, reg, val, val_len);