diff options
| author | Jean Delvare <khali@linux-fr.org> | 2009-12-06 17:06:17 +0100 |
|---|---|---|
| committer | Jean Delvare <khali@linux-fr.org> | 2009-12-06 17:06:17 +0100 |
| commit | 6f7e549f873e9ff10a4a27241db568bf7988ee0c (patch) | |
| tree | 7b8d37442fe3b6ebbaedda63deb65276a2371c9b | |
| parent | dddc66ffa048fbc842f5de385031f1826649ffc2 (diff) | |
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: Jean Delvare <khali@linux-fr.org>
Tested-by: Michel Daenzer <michel@daenzer.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
| -rw-r--r-- | drivers/i2c/busses/i2c-powermac.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-powermac.c b/drivers/i2c/busses/i2c-powermac.c index 3c9d71f6018..a74f3bab05b 100644 --- a/drivers/i2c/busses/i2c-powermac.c +++ b/drivers/i2c/busses/i2c-powermac.c @@ -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; |