commit: http://blackfin.uclinux.org/git/?p=linux-kernel;a=commitdiff;h=3d427e2caa048f231856cf301d5d36b230944298 branch: http://blackfin.uclinux.org/git/?p=linux-kernel;a=shortlog;h=refs/heads/2011R1
When doing a single register write we use work_buf for both the register and the value with the buffer formatted for sending directly to the device so we can just do a write() directly. This saves allocating a temporary buffer if we can't do gather writes and is likely to be faster than doing a gather write. Signed-off-by: Mark Brown <[email protected]> --- drivers/base/regmap/regmap.c | 12 +++++++++--- 1 files changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index fb89e21..02ed154 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -211,13 +211,19 @@ static int _regmap_raw_write(struct regmap *map, unsigned int reg, map->format.format_reg(map->work_buf, reg); - /* Try to do a gather write if we can */ - if (map->bus->gather_write) + /* If we're doing a single register write we can probably just + * send the work_buf directly, otherwise try to do a gather + * write. + */ + if (val == map->work_buf + map->format.reg_bytes) + ret = map->bus->write(map->dev, map->work_buf, + map->format.reg_bytes + val_len); + else if (map->bus->gather_write) ret = map->bus->gather_write(map->dev, map->work_buf, map->format.reg_bytes, val, val_len); - /* Otherwise fall back on linearising by hand. */ + /* If that didn't work fall back on linearising by hand. */ if (ret == -ENOTSUPP) { len = map->format.reg_bytes + val_len; buf = kmalloc(len, GFP_KERNEL);
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