From 2547e201b3693f91d643fc0d21ef86171894b59b Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Wed, 20 Jul 2011 21:47:22 +0100 Subject: [PATCH] regmap: Just send the buffer directly for single register writes 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 --- drivers/base/regmap/regmap.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index cf3565c..6aa2c4b 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -202,13 +202,19 @@ 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); -- 2.7.4