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regmap: Use _regmap_read in regmap_bulk_read

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Bulk reads may potentially read a lot of registers and regmap_read will
take and release the regmap lock for each register. Avoid bouncing
the lock so frequently by holding the lock locally and calling
_regmap_read instead. This also has the nice side-effect that all the
reads will be done atomically so no other threads can sneak a write in
during the regmap_bulk_read.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Charles Keepax 2018-02-15 17:52:18 +00:00 committed by Mark Brown
parent 1b079ca2c2
commit 186ba2eec2
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GPG Key ID: 24D68B725D5487D0
1 changed files with 13 additions and 5 deletions
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18
drivers/base/regmap/regmap.c
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@ -2674,6 +2674,8 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
if (!IS_ALIGNED(reg, map->reg_stride))
return -EINVAL;
if (val_count == 0)
return -EINVAL;
if (map->bus && map->format.parse_inplace && (vol || map->cache_type == REGCACHE_NONE)) {
ret = regmap_raw_read(map, reg, val, val_bytes * val_count);
@ -2690,13 +2692,15 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
u16 *u16 = val;
u8 *u8 = val;
map->lock(map->lock_arg);
for (i = 0; i < val_count; i++) {
unsigned int ival;
ret = regmap_read(map, reg + regmap_get_offset(map, i),
&ival);
ret = _regmap_read(map, reg + regmap_get_offset(map, i),
&ival);
if (ret != 0)
return ret;
goto out;
switch (map->format.val_bytes) {
#ifdef CONFIG_64BIT
@ -2714,12 +2718,16 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
u8[i] = ival;
break;
default:
return -EINVAL;
ret = -EINVAL;
goto out;
}
}
out:
map->unlock(map->lock_arg);
}
return 0;
return ret;
}
EXPORT_SYMBOL_GPL(regmap_bulk_read);