Unverified Commit eab5abde authored by Mark Brown's avatar Mark Brown
Browse files

regmap: Check for register readability before checking cache during read 



Ensure that we don't return a spurious cache hit for unreadable registers
(eg, with the flat cache which doesn't understand sparseness) by checking
for readability before we do a cache lookup.

Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230613-b4-regmap-check-readability-before-cache-v1-1-b144c0b01ed9@kernel.org


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent b629c698

drivers/base/regmap/regmap.c

+3 −3
Original line number Diff line number Diff line
@@ -2897,6 +2897,9 @@ static int _regmap_read(struct regmap *map, unsigned int reg, 
	int ret;

	void *context = _regmap_map_get_context(map);



	if (!regmap_readable(map, reg))

		return -EIO;



	if (!map->cache_bypass) {

		ret = regcache_read(map, reg, val);

		if (ret == 0)
@@ -2906,9 +2909,6 @@ static int _regmap_read(struct regmap *map, unsigned int reg, 
	if (map->cache_only)

		return -EBUSY;



	if (!regmap_readable(map, reg))

		return -EIO;



	ret = map->reg_read(context, reg, val);

	if (ret == 0) {

		if (regmap_should_log(map))