The patch regmap: Use _regmap_read in regmap_bulk_read has been applied to the regmap tree at https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >From 186ba2eec275a5e4ee09d4b6a77c619e46fab9fd Mon Sep 17 00:00:00 2001 From: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx> Date: Thu, 15 Feb 2018 17:52:18 +0000 Subject: [PATCH] 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@xxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> --- drivers/base/regmap/regmap.c | 18 +++++++++++++----- 1 file 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); -- 2.16.1 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
