| Message ID | 20090930221435.58636363@hyperion.delvare (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Wed, 2009-09-30 at 22:14 +0200, Jean Delvare wrote: > 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> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Cc: Paul Mackerras <paulus@samba.org> > --- > 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; > >
--- 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;
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> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> --- drivers/i2c/busses/i2c-powermac.c | 6 ++++++ 1 file changed, 6 insertions(+)