regmap: cache: Fix num_reg_defaults computation from reg_defaults_raw

In 3245d460 (regmap: cache: Fall back to register by register read for
cache defaults) non-readable registers are skipped when initializing
reg_defaults, but are still included in num_reg_defaults. So there can
be uninitialized entries at the end of reg_defaults, which can cause
problems when the register cache initializes from the full array.

Fixed it by excluding non-readable registers from the count as well.

Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index df7ff72908216f5d7a97f03af3f06ae4fd5adefd..4e582561e1e7a0cdffeaf8b3901d3a56d66a37ad 100644 (file)
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -38,10 +38,11 @@ static int regcache_hw_init(struct regmap *map)
 
        /* calculate the size of reg_defaults */
        for (count = 0, i = 0; i < map->num_reg_defaults_raw; i++)
-               if (!regmap_volatile(map, i * map->reg_stride))
+               if (regmap_readable(map, i * map->reg_stride) &&
+                   !regmap_volatile(map, i * map->reg_stride))
                        count++;
 
-       /* all registers are volatile, so just bypass */
+       /* all registers are unreadable or volatile, so just bypass */
        if (!count) {
                map->cache_bypass = true;
                return 0;