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| author | Charles Keepax <ckeepax@opensource.cirrus.com> | 2018-02-15 17:52:18 +0000 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2018-02-16 12:03:30 +0000 |
| commit | 186ba2eec275a5e4ee09d4b6a77c619e46fab9fd (patch) | |
| tree | 7131a29eed8fca67a833a37ea0bdcc54ccad6ddc /drivers/base | |
| parent | 1b079ca2c2e9a4652051bc4b62a5ef83d59d86bb (diff) | |
| download | talos-obmc-linux-186ba2eec275a5e4ee09d4b6a77c619e46fab9fd.tar.gz talos-obmc-linux-186ba2eec275a5e4ee09d4b6a77c619e46fab9fd.zip | |
regmap: Use _regmap_read in regmap_bulk_read
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>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/regmap/regmap.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index ff30a9157de5..258a40e2a1d3 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -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); |
