From khali@linux-fr.org Wed Jan 18 14:14:09 2006 Date: Wed, 18 Jan 2006 23:14:55 +0100 From: Jean Delvare To: Greg KH Subject: [PATCH 12/17] i2c: Speed up block transfers Message-Id: <20060118231455.71b0c12e.khali@linux-fr.org> Content-Disposition: inline; filename=i2c-speedup-block-transfers.patch 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: Jean Delvare Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/i2c-core.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) --- gregkh-2.6.orig/drivers/i2c/i2c-core.c +++ gregkh-2.6/drivers/i2c/i2c-core.c @@ -920,12 +920,11 @@ s32 i2c_smbus_write_block_data(struct i2 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); @@ -935,16 +934,14 @@ s32 i2c_smbus_write_block_data(struct i2 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]; - return data.block[0]; - } + + 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,