[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: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 6 insertions, 9 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 97334433e53..2b0c555aa01 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -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);
@@ -935,16 +934,14 @@ 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];
-                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,