From: Mark Brown Date: Wed, 3 Aug 2011 00:52:39 +0000 (+1000) Subject: When doing a single register write we use work_buf for both the register X-Git-Tag: next-20110805~1^2~68 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=facc67cfb7f7ad865a3cd55864adc31f4a7a8e9f;p=karo-tx-linux.git 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 Cc: Greg KH Signed-off-by: Andrew Morton --- diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 0eef4da1ac61..60d94fe68213 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -202,13 +202,20 @@ 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 + + map->format.val_bytes); + 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);