[PATCH] i2c-powermac: Reject unsupported I2C transactions
From: Jean Delvare <hidden>
Date: 2009-09-30 20:14:39
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 <redacted> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <redacted> --- drivers/i2c/busses/i2c-powermac.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- linux-2.6.32-rc1.orig/drivers/i2c/busses/i2c-powermac.c 2009-06-10 05:05:27.000000000 +0200
+++ linux-2.6.32-rc1/drivers/i2c/busses/i2c-powermac.c 2009-09-30 20:29:42.000000000 +0200@@ -146,6 +146,12 @@ static int i2c_powermac_master_xfer( str 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;
--
Jean Delvare