regmap: Don't attempt block writes when syncing cache on single_rw devices

commit 5c1ebe7f upstream.

If the device can't support block writes then don't attempt to use raw
syncing which will automatically generate block writes for adjacent
registers, use the existing _single() block syncing implementation.
Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/regmap/regcache.c

@@ -698,7 +698,7 @@ int regcache_sync_block(struct regmap *map, void *block,
 			unsigned int block_base, unsigned int start,
 			unsigned int end)
 {
-	if (regmap_can_raw_write(map))
+	if (regmap_can_raw_write(map) && !map->use_single_rw)
 		return regcache_sync_block_raw(map, block, cache_present,
 					       block_base, start, end);
 	else