[PATCH] regmap: cache: Fix num_reg_defaults computation from reg_defaults_raw

From: Maarten ter Huurne
Date: Fri Jul 29 2016 - 17:42:12 EST


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@xxxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
drivers/base/regmap/regcache.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index df7ff7290821..4e582561e1e7 100644
--- 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;
--
2.8.1