Commit 7656032b authored by Jean Delvare's avatar Jean Delvare Committed by Greg Kroah-Hartman
Browse files

[PATCH] i2c: Speed up block transfers 



Speed up i2c_smbus_write_block_data and i2c_smbus_read_i2c_block_data
a bit by using memcpy instead of an explicit loop.

Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 93766d2d

drivers/i2c/i2c-core.c

+6 −9
Original line number Diff line number Diff line
@@ -920,12 +920,11 @@ s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, 
			       u8 length, u8 *values)

{

	union i2c_smbus_data data;

	int i;



	if (length > I2C_SMBUS_BLOCK_MAX)

		length = I2C_SMBUS_BLOCK_MAX;

	for (i = 1; i <= length; i++)

		data.block[i] = values[i-1];

	data.block[0] = length;

	memcpy(&data.block[1], values, length);

	return i2c_smbus_xfer(client->adapter,client->addr,client->flags,

			      I2C_SMBUS_WRITE,command,

			      I2C_SMBUS_BLOCK_DATA,&data);
@@ -935,17 +934,15 @@ s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, 
s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, u8 *values)

{

	union i2c_smbus_data data;

	int i;



	if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,

	                      I2C_SMBUS_READ,command,

	                      I2C_SMBUS_I2C_BLOCK_DATA,&data))

		return -1;

	else {

		for (i = 1; i <= data.block[0]; i++)

			values[i-1] = data.block[i];



	memcpy(values, &data.block[1], data.block[0]);

	return data.block[0];

}

}



s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command,

				   u8 length, u8 *values)