Re: [PATCH] Staging: comedi: clean up conditional statement in addi_apci_3xxx.c

[Ian Abbott]

On 2014-02-13 10:08, Ian Abbott wrote:
> On 2014-02-13 03:29, Chase Southwood wrote:
> > In this if-else conditional statement, if (chan < 16), but
> > (data[0] == INSN_CONFIG_DIO_QUERY), the function does not return early,
> > but the else-branch does not get executed either.  As a result, mask
> > would be used uninitialized in the next line.  What we want here is if
> > (chan < 16) and (data[0] != INSN_CONFIG_DIO_QUERY), return an error, but
> > in every other case, initialize mask and then proceed.  Found by a static
> > checker.
> >
> > Signed-off-by: Chase Southwood <chase.southwood@xxxxxxxxx>
> > ---
> >   drivers/staging/comedi/drivers/addi_apci_3xxx.c | 12 +++++-------
> >   1 file changed, 5 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/staging/comedi/drivers/addi_apci_3xxx.c
> > b/drivers/staging/comedi/drivers/addi_apci_3xxx.c
> > index ceadf8e..04c5153 100644
> > --- a/drivers/staging/comedi/drivers/addi_apci_3xxx.c
> > +++ b/drivers/staging/comedi/drivers/addi_apci_3xxx.c
> > @@ -688,13 +688,11 @@ static int apci3xxx_dio_insn_config(struct
> > comedi_device *dev,
> >        * Port 1 (channels 8-15) are always outputs
> >        * Port 2 (channels 16-23) are programmable i/o
> >        */
> > -    if (chan < 16) {
> > -        if (data[0] != INSN_CONFIG_DIO_QUERY)
> > -            return -EINVAL;
> > -    } else {
> > -        /* changing any channel in port 2 changes the entire port */
> > -        mask = 0xff0000;
> > -    }
> > +    if ((chan < 16) && (data[0] != INSN_CONFIG_DIO_QUERY))
> > +        return -EINVAL;
> > +
> > +    /* changing any channel in port 2 changes the entire port */
> > +    mask = 0xff0000;
> >
> >       ret = comedi_dio_insn_config(dev, s, insn, data, mask);
> >       if (ret)
>
> Seems correct.
>
> Acked-by: Ian Abbott <abbotti@xxxxxxxxx>

Okay, as Hartley pointed out, it isn't correct, so I withdraw my 
"Acked-by".

--
-=( Ian Abbott @ MEV Ltd.    E-mail: <abbotti@xxxxxxxxx>        )=-
-=( Tel: +44 (0)161 477 1898   FAX: +44 (0)161 718 3587         )=-
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