HI Jacopo,
On 15 October 2018 08:54 jacopo mondi wrote:
> On Fri, Oct 12, 2018 at 11:40:36AM +0100, Phil Edworthy wrote:
> > This fixes the check for unused mdio bus setting and the following
> > static checker warning:
> > drivers/pinctrl/pinctrl-rzn1.c:198 rzn1_pinctrl_mdio_select()
> > warn: always true condition '(ipctl->mdio_func[mdio] >= 0) => (0-u32max
> >= 0)'
> >
> > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > Signed-off-by: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>
> > ---
> > drivers/pinctrl/pinctrl-rzn1.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/pinctrl/pinctrl-rzn1.c
> > b/drivers/pinctrl/pinctrl-rzn1.c index ce05e3a00be2..f688f3a29dfd
> > 100644
> > --- a/drivers/pinctrl/pinctrl-rzn1.c
> > +++ b/drivers/pinctrl/pinctrl-rzn1.c
> > @@ -195,7 +195,7 @@ static void rzn1_hw_set_lock(struct rzn1_pinctrl
> > *ipctl, u8 lock, u8 value) static void rzn1_pinctrl_mdio_select(struct
> rzn1_pinctrl *ipctl, int mdio,
> > u32 func)
> > {
> > - if (ipctl->mdio_func[mdio] >= 0 && ipctl->mdio_func[mdio] != func)
> > + if (ipctl->mdio_func[mdio] != -1 && ipctl->mdio_func[mdio] != func)
> > dev_warn(ipctl->dev, "conflicting setting for mdio%d!\n",
> mdio);
> > ipctl->mdio_func[mdio] = func;
> >
>
> MY understanding here is that the static checker complains because you are
> comparing a variable of unsigned type to negative values, and indeed you are
> treating mdio_func as signed in the driver code.
>
> mdio_func is defined as:
>
> struct rzn1_pinctrl {
> ...
> u32 mdio_func[2];
> ...
> };
>
> Then in probe function mdio_func gets intialized as:
>
> ipctl->mdio_func[0] = -1;
> ipctl->mdio_func[1] = -1;
>
> I think you could safely make mdio_func integers, or either define an
> INVALID value ( > 0), intialize them it that value and check against it for
> validity.
You are right, I shouldn't rely on the implicit typecast from -1 to uint.
I'll send an updated patch to fix this.
Thanks
Phil
