commit bb2bb45d1be28987e6cb50f50e4819795537ab83
author Mark Brown <broonie@kernel.org> Mon Feb 01 21:09:14 2016 +0000
committer Mark Brown <broonie@kernel.org> Mon Feb 01 21:11:38 2016 +0000
tree fe74c7504043119b2f4f1ba67adf8d8ef224f220
parent 922a9f936e40001f9b921379aab90047d5990923

regmap: Return an error if a caller attempts to do an unsupported raw read

regmaps without raw I/O access can't implement raw I/O operations,
return an error if someone tries to do that rather than crashing.

Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/base/regmap/regmap.c

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 3432634..e2f6880 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -2255,6 +2255,9 @@
 
 	WARN_ON(!map->bus);
 
+	if (!map->bus || !map->bus->read)
+		return -EINVAL;
+
 	range = _regmap_range_lookup(map, reg);
 	if (range) {
 		ret = _regmap_select_page(map, &reg, range,