Commit 6f7e549f authored by Jean Delvare's avatar Jean Delvare

i2c-powermac: Reject unsupported I2C transactions

The i2c-powermac driver doesn't support arbitrary multi-message I2C
transactions, only SMBus ones. Make it clear by returning an error if
a multi-message I2C transaction is attempted. This is better than only
processing the first message, because most callers won't recover from
the short transaction. Anyone wishing to issue multi-message
transactions should use the SMBus API instead of the raw I2C API.
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
Tested-by: default avatarMichel Daenzer <michel@daenzer.net>
Acked-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
parent dddc66ff
......@@ -146,6 +146,12 @@ static int i2c_powermac_master_xfer( struct i2c_adapter *adap,
int read;
int addrdir;
if (num != 1) {
dev_err(&adap->dev,
"Multi-message I2C transactions not supported\n");
return -EOPNOTSUPP;
}
if (msgs->flags & I2C_M_TEN)
return -EINVAL;
read = (msgs->flags & I2C_M_RD) != 0;
......
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