From a00b597302a3012fe16ac38631cc7227a49f181d Mon Sep 17 00:00:00 2001
From: Lars-Peter Clausen <lars@metafoo.de>
Date: Wed, 15 Feb 2012 10:23:25 +0100
Subject: [PATCH] regmap: Fix cache defaults initialization from raw cache
defaults
Currently registers with a value of 0 are ignored when initializing the register
defaults from raw defaults. This worked in the past, because registers without a
explicit default were assumed to have a default value of 0. This was changed in
commit 3376a934 ("regmap: Ensure rbtree syncs registers set to zero properly").
As a result registers, which have a raw default value of 0 are now assumed to
have no default. This again can result in unnecessary writes when syncing the
cache. It will also result in unnecessary reads for e.g. the first update
operation. In the case where readback is not possible this will even let the
update operation fail, if the register has not been written to before.
So this patch removes the check. Instead it adds a check to ignore raw defaults
for registers which are volatile, since those registers are not cached.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org
---
drivers/base/regmap/regcache.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 1ead66186b7c0..d1daa5e9fadf3 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -53,7 +53,7 @@ static int regcache_hw_init(struct regmap *map)
for (count = 0, i = 0; i < map->num_reg_defaults_raw; i++) {
val = regcache_get_val(map->reg_defaults_raw,
i, map->cache_word_size);
- if (!val)
+ if (regmap_volatile(map, i))
continue;
count++;
}
@@ -70,7 +70,7 @@ static int regcache_hw_init(struct regmap *map)
for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) {
val = regcache_get_val(map->reg_defaults_raw,
i, map->cache_word_size);
- if (!val)
+ if (regmap_volatile(map, i))
continue;
map->reg_defaults[j].reg = i;
map->reg_defaults[j].def = val;
--
2.39.5