From 4c4d887822070410e3be519e1a4ff933fb899ba8 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Thu, 17 Mar 2011 21:40:51 +0000 Subject: mfd: Remove copy from WM831x I2C write function This saves us allocating an array on the stack, giving a meaningless performance improvement and ensuring that if drivers ever do large writes we'll not allocate large arrays on the stack. Signed-off-by: Mark Brown Signed-off-by: Samuel Ortiz --- drivers/mfd/wm831x-i2c.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'drivers/mfd/wm831x-i2c.c') diff --git a/drivers/mfd/wm831x-i2c.c b/drivers/mfd/wm831x-i2c.c index 3853fa8..a06cbc7 100644 --- a/drivers/mfd/wm831x-i2c.c +++ b/drivers/mfd/wm831x-i2c.c @@ -51,17 +51,25 @@ static int wm831x_i2c_write_device(struct wm831x *wm831x, unsigned short reg, int bytes, void *src) { struct i2c_client *i2c = wm831x->control_data; - unsigned char msg[bytes + 2]; + struct i2c_msg xfer[2]; int ret; reg = cpu_to_be16(reg); - memcpy(&msg[0], ®, 2); - memcpy(&msg[2], src, bytes); - ret = i2c_master_send(i2c, msg, bytes + 2); + xfer[0].addr = i2c->addr; + xfer[0].flags = 0; + xfer[0].len = 2; + xfer[0].buf = (char *)® + + xfer[1].addr = i2c->addr; + xfer[1].flags = I2C_M_NOSTART; + xfer[1].len = bytes; + xfer[1].buf = (char *)src; + + ret = i2c_transfer(i2c->adapter, xfer, 2); if (ret < 0) return ret; - if (ret < bytes + 2) + if (ret != 2) return -EIO; return 0; -- cgit v1.1