Messages in this thread Patch in this message | | | Date | Mon, 27 Feb 2012 17:04:37 -0800 | From | Greg KH <> | Subject | [ 08/72] regmap: Fix cache defaults initialization from raw cache defaults |
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3.2-stable review patch. If anyone has any objections, please let me know.
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From: Lars-Peter Clausen <lars@metafoo.de>
commit 61cddc57dc14a5dffa0921d9a24fd68edbb374ac upstream.
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 b03622a8 ("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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/base/regmap/regcache.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/base/regmap/regcache.c +++ b/drivers/base/regmap/regcache.c @@ -54,7 +54,7 @@ static int regcache_hw_init(struct regma 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++; } @@ -69,7 +69,7 @@ static int regcache_hw_init(struct regma 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;
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