Re: [PATCH] i2c: taos-evm: replace simple_strtoul by kstrtou8

[LABBE Corentin <montjoie.mailing@gmail.com>]

On Thu, Nov 12, 2015 at 08:46:43AM +0100, Uwe Kleine-König wrote:
> On Thu, Nov 12, 2015 at 08:26:33AM +0100, LABBE Corentin wrote:
> > The simple_strtoul function is marked as obsolete.
> > This patch replace it by kstrtou8.
> > 
> > Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
> > ---
> >  drivers/i2c/busses/i2c-taos-evm.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/i2c/busses/i2c-taos-evm.c b/drivers/i2c/busses/i2c-taos-evm.c
> > index 4c7fc2d..fe2b705 100644
> > --- a/drivers/i2c/busses/i2c-taos-evm.c
> > +++ b/drivers/i2c/busses/i2c-taos-evm.c
> > @@ -70,6 +70,7 @@ static int taos_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
> >  	struct serio *serio = adapter->algo_data;
> >  	struct taos_data *taos = serio_get_drvdata(serio);
> >  	char *p;
> > +	int err;
> >  
> >  	/* Encode our transaction. "@" is for the device address, "$" for the
> >  	   SMBus command and "#" for the data. */
> > @@ -130,7 +131,9 @@ static int taos_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
> >  			return 0;
> >  	} else {
> >  		if (p[0] == 'x') {
> > -			data->byte = simple_strtol(p + 1, NULL, 16);
> > +			err = kstrtou8(p + 1, 16, &data->byte);
> > +			if (err)
> > +				return -EPROTO;
> >  			return 0;
> 
> This is nearly equivalent to the probably more correct:
> 
> 	return kstrtou8(p + 1, 16, &data->byte);
> 

As reported, by Jean Delvare, kstrtou8 could return -EINVAL.
It is why I "drop" the return code from kstrtou8 and return -EPROTO as suggested by Jean.

I have hesitate to put a comment for this, and it seems finaly necessary.

Regards