[PATCH] regmap: regmap_raw_read return error on !bus->read

[Markus Pargmann]

Return -ENOTSUPP if map->bus->read is not implemented and we do not use
the cache. This code path would directly use bus->read would run into an
NULL pointer for the read function.

Signed-off-by: Markus Pargmann <mpa@xxxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
 drivers/base/regmap/regmap.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 7111d04..fc14a7c 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -2184,6 +2184,11 @@ 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);
 
-- 
2.5.0

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