Re: [PATCH] char: mwave: smapi: Make usSmapiOK signed to fix warning

[Purva Yeshi]

On 15/04/25 20:22, Greg KH wrote:
> On Thu, Apr 10, 2025 at 02:49:29AM +0530, Purva Yeshi wrote:
> > Fix Smatch-detected warning:
> > drivers/char/mwave/smapi.c:69 smapi_request() warn:
> > assigning (-5) to unsigned variable 'usSmapiOK'
> >
> > Assigning a negative value (-EIO, which is -5) to an unsigned short
> > (usSmapiOK) causes a Smatch warning because negative values cannot
> > be correctly represented in an unsigned type, leading to unexpected
> > behavior.
> >
> > Change the type of usSmapiOK from unsigned short to short to allow
> > storing negative values like -EIO without causing a type mismatch or
> > logic error.
> >
> > Signed-off-by: Purva Yeshi <purvayeshi550@xxxxxxxxx>
> > ---
> >   drivers/char/mwave/smapi.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/char/mwave/smapi.c b/drivers/char/mwave/smapi.c
> > index f8d79d393b69..37da1339357e 100644
> > --- a/drivers/char/mwave/smapi.c
> > +++ b/drivers/char/mwave/smapi.c
> > @@ -66,7 +66,7 @@ static int smapi_request(unsigned short inBX, unsigned short inCX,
> >   	unsigned short myoutDX = 5, *pmyoutDX = &myoutDX;
> >   	unsigned short myoutDI = 6, *pmyoutDI = &myoutDI;
> >   	unsigned short myoutSI = 7, *pmyoutSI = &myoutSI;
> > -	unsigned short usSmapiOK = -EIO, *pusSmapiOK = &usSmapiOK;
> > +	short usSmapiOK = -EIO, *pusSmapiOK = &usSmapiOK;
>
> This no longer a "us" variable type :(
>
> The joy of using this type of notation, ick.  Please fix this up to use
> an explicit type (like s16), and fix the variable name at the same time.
>
> thanks,
>
> greg k-h

Hi Greg,

Thanks for the feedback.

I’ll update the patch to use an explicit s16 type and rename the 
usSmapiOK with SmapiOK to match the new type. I’ll send a v2 shortly.

Best regards,
Purva