1 files changed, 19 insertions, 20 deletions

diff --git a/drivers/i2c/chips/eeprom.c b/drivers/i2c/chips/eeprom.c
index 213a9f98decc..9a81252a7218 100644
--- a/drivers/i2c/chips/eeprom.c
+++ b/drivers/i2c/chips/eeprom.c
@@ -78,7 +78,7 @@ static struct i2c_driver eeprom_driver = {
 static void eeprom_update_client(struct i2c_client *client, u8 slice)
 {
         struct eeprom_data *data = i2c_get_clientdata(client);
-        int i, j;
+        int i;
 
         mutex_lock(&data->update_lock);
 
@@ -93,15 +93,12 @@ static void eeprom_update_client(struct i2c_client *client, u8 slice)
                                                         != 32)
                                         goto exit;
                 } else {
-                        if (i2c_smbus_write_byte(client, slice << 5)) {
-                                dev_dbg(&client->dev, "eeprom read start has failed!\n");
-                                goto exit;
-                        }
-                        for (i = slice << 5; i < (slice + 1) << 5; i++) {
-                                j = i2c_smbus_read_byte(client);
-                                if (j < 0)
+                        for (i = slice << 5; i < (slice + 1) << 5; i += 2) {
+                                int word = i2c_smbus_read_word_data(client, i);
+                                if (word < 0)
                                         goto exit;
-                                data->data[i] = (u8) j;
+                                data->data[i] = word & 0xff;
+                                data->data[i + 1] = word >> 8;
                         }
                 }
                 data->last_updated[slice] = jiffies;
@@ -177,14 +174,15 @@ static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind)
         if (!(adapter->class & I2C_CLASS_SPD) && address >= 0x51)
                 goto exit;
 
-        /* There are three ways we can read the EEPROM data:
+        /* There are four ways we can read the EEPROM data:
            (1) I2C block reads (faster, but unsupported by most adapters)
-           (2) Consecutive byte reads (100% overhead)
-           (3) Regular byte data reads (200% overhead)
-           The third method is not implemented by this driver because all
-           known adapters support at least the second. */
-        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA
-                                            | I2C_FUNC_SMBUS_BYTE))
+           (2) Word reads (128% overhead)
+           (3) Consecutive byte reads (88% overhead, unsafe)
+           (4) Regular byte data reads (265% overhead)
+           The third and fourth methods are not implemented by this driver
+           because all known adapters support one of the first two. */
+        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)
+         && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
                 goto exit;
 
         if (!(data = kzalloc(sizeof(struct eeprom_data), GFP_KERNEL))) {
@@ -212,13 +210,14 @@ static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind)
 
         /* Detect the Vaio nature of EEPROMs.
            We use the "PCG-" or "VGN-" prefix as the signature. */
-        if (address == 0x57) {
+        if (address == 0x57
+         && i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
                 char name[4];
 
                 name[0] = i2c_smbus_read_byte_data(new_client, 0x80);
-                name[1] = i2c_smbus_read_byte(new_client);
-                name[2] = i2c_smbus_read_byte(new_client);
-                name[3] = i2c_smbus_read_byte(new_client);
+                name[1] = i2c_smbus_read_byte_data(new_client, 0x81);
+                name[2] = i2c_smbus_read_byte_data(new_client, 0x82);
+                name[3] = i2c_smbus_read_byte_data(new_client, 0x83);
 
                 if (!memcmp(name, "PCG-", 4) || !memcmp(name, "VGN-", 4)) {
                         dev_info(&new_client->dev, "Vaio EEPROM detected, "