Merge tag 'regmap-fix-v7.1-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap fix from Mark Brown:
 "Some other fixing in an API user turned up the fact that we weren't
  correctly applying cache only mode to volatile registers in
  regmap_update_bits(), causing us to try to access hardware that was
  powered off or otherwise not in a state to accept I/O. This fix
  returns an error instead, avoiding more serious consequences"

* tag 'regmap-fix-v7.1-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: reject volatile update_bits() in cache-only mode

drivers/base/regmap/regmap.c

@@ -3257,6 +3257,9 @@ static int _regmap_update_bits(struct regmap *map, unsigned int reg,
 		*change = false;
 
 	if (regmap_volatile(map, reg) && map->reg_update_bits) {
+		if (map->cache_only)
+			return -EBUSY;
+
 		reg = regmap_reg_addr(map, reg);
 		ret = map->reg_update_bits(map->bus_context, reg, mask, val);
 		if (ret == 0 && change)