i2c-i801: Don't use the block buffer for I2C block writes

commit c074c39d62306efa5ba7c69c1a1531bc7333d252 upstream.

Experience has shown that the block buffer can only be used for SMBus
(not I2C) block transactions, even though the datasheet doesn't
mention this limitation.

Reported-by: Felix Rubinstein <felixru@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Oleg Ryjkov <oryjkov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index df6ab553f975c98ed078475454d35a58d272aef7..5574be2ae6f933c1b3538d3a1091d52fd6ac31e3 100644 (file)
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -415,9 +415,11 @@ static int i801_block_transaction(union i2c_smbus_data *data, char read_write,
                data->block[0] = 32;    /* max for SMBus block reads */
        }
 
+       /* Experience has shown that the block buffer can only be used for
+          SMBus (not I2C) block transactions, even though the datasheet
+          doesn't mention this limitation. */
        if ((i801_features & FEATURE_BLOCK_BUFFER)
-        && !(command == I2C_SMBUS_I2C_BLOCK_DATA
-             && read_write == I2C_SMBUS_READ)
+        && command != I2C_SMBUS_I2C_BLOCK_DATA
         && i801_set_block_buffer_mode() == 0)
                result = i801_block_transaction_by_block(data, read_write,
                                                         hwpec);