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-sis630.c b/drivers/i2c/busses/i2c-sis630.c
index c4cc5eddf50d..d7e6ff3e0187 100644
--- a/drivers/i2c/busses/i2c-sis630.c
+++ b/drivers/i2c/busses/i2c-sis630.c
@@ -356,7 +356,8 @@ static s32 sis630_access(struct i2c_adapter *adap, u16 addr,
                         size = SIS630_BLOCK_DATA;
                         return sis630_block_data(adap, data, read_write);
                 default:
-                        printk("Unsupported SMBus operation\n");
+                        dev_warn(&adap->dev, "Unsupported transaction %d\n",
+                                 size);
                         return -EOPNOTSUPP;
         }
 
@@ -378,8 +379,6 @@ static s32 sis630_access(struct i2c_adapter *adap, u16 addr,
                 case SIS630_WORD_DATA:
                         data->word = sis630_read(SMB_BYTE) + (sis630_read(SMB_BYTE + 1) << 8);
                         break;
-                default:
-                        return -EOPNOTSUPP;
         }
 
         return 0;