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Commit 4c4d8878 authored by Mark Brown's avatar Mark Brown Committed by Samuel Ortiz
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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: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent aad34310

drivers/mfd/wm831x-i2c.c

+13 −5
Original line number Diff line number Diff line
@@ -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], &reg, 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 *)&reg;



	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;