regmap: cache: Return error in cache sync operations for REGCACHE_NONE

BugLink: https://bugs.launchpad.net/bugs/2028808
[ Upstream commit fd883d79e4dcd2417c2b80756f22a2ff03b0f6e0 ]

There is no sense in doing a cache sync on REGCACHE_NONE regmaps.
Instead of panicking the kernel due to missing cache_ops, return an error
to client driver.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20230313071812.13577-1-alexander.stein@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 362e043e26d86792ed44793f251ae2428c5bf426..8031007b4887dfe40b1dafa5c6fd17a27ad2b898 100644 (file)
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -349,6 +349,9 @@ int regcache_sync(struct regmap *map)
        const char *name;
        bool bypass;
 
+       if (WARN_ON(map->cache_type == REGCACHE_NONE))
+               return -EINVAL;
+
        BUG_ON(!map->cache_ops);
 
        map->lock(map->lock_arg);
@@ -418,6 +421,9 @@ int regcache_sync_region(struct regmap *map, unsigned int min,
        const char *name;
        bool bypass;
 
+       if (WARN_ON(map->cache_type == REGCACHE_NONE))
+               return -EINVAL;
+
        BUG_ON(!map->cache_ops);
 
        map->lock(map->lock_arg);