i2c: Consistently reject unsupported transactions

Many PC SMBus host controller drivers don't properly handle the case
where they are requested to achieve a transaction they do not support.
Update them so that the consistently print a warning message and
return a single error value in this case.

Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 2 insertions, 3 deletions

diff --git a/drivers/i2c/busses/i2c-taos-evm.c b/drivers/i2c/busses/i2c-taos-evm.c
index de9db49e54d9..224aa12ee7c8 100644
--- a/drivers/i2c/busses/i2c-taos-evm.c
+++ b/drivers/i2c/busses/i2c-taos-evm.c
@@ -96,9 +96,8 @@ static int taos_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
                         sprintf(p, "$%02X", command);
                 break;
         default:
-                dev_dbg(&adapter->dev, "Unsupported transaction size %d\n",
-                        size);
-                return -EINVAL;
+                dev_warn(&adapter->dev, "Unsupported transaction %d\n", size);
+                return -EOPNOTSUPP;
         }
 
         /* Send the transaction to the TAOS EVM */