[Linux-kernel-mentees] [PATCH] staging: media: bcm2048: Fixed style error ERROR: Macros with complex values should be enclosed in parentheses found using scripts/checkpatch.pl

[gregkh at linuxfoundation.org (Greg KH)]

On Mon, Apr 29, 2019 at 10:47:55PM +0530, Puranjay Mohan wrote:
> On Mon, Apr 29, 2019 at 09:34:41AM -0600, Shuah Khan wrote:
> > On 4/29/19 9:17 AM, Puranjay Mohan wrote:
> > > On Mon, Apr 29, 2019 at 04:56:35PM +0200, Greg KH wrote:
> > > > On Mon, Apr 29, 2019 at 08:20:02PM +0530, Puranjay Mohan wrote:
> > > > > Signed-off-by: Puranjay Mohan <puranjay12 at gmail.com>
> > > > > ---
> > > > 
> > > > I think your subject line needs a bit of work :)
> > > > 
> > > > Also, I can't take patches without any changelog text.
> > > > 
> > > > >   drivers/staging/media/bcm2048/radio-bcm2048.c | 2 +-
> > > > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > > > > 
> > > > > diff --git a/drivers/staging/media/bcm2048/radio-bcm2048.c b/drivers/staging/media/bcm2048/radio-bcm2048.c
> > > > > index d9b02ff66259..599da6c977ed 100644
> > > > > --- a/drivers/staging/media/bcm2048/radio-bcm2048.c
> > > > > +++ b/drivers/staging/media/bcm2048/radio-bcm2048.c
> > > > > @@ -2000,7 +2000,7 @@ static ssize_t bcm2048_##prop##_read(struct device *dev,		\
> > > > >   	return sprintf(buf, mask "\n", value);				\
> > > > >   }
> > > > > -#define DEFINE_SYSFS_PROPERTY(prop, prop_type, mask, check)		\
> > > > > +#define (DEFINE_SYSFS_PROPERTY(prop, prop_type, mask, check))		\
> > > > >   property_write(prop, prop_type, mask, check)				\
> > > > >   property_read(prop, mask)						\
> > > > 
> > > > Wait, did you build this patch?  Are you sure it is doing what you think
> > > > it is doing?
> > > > 
> > > > thanks,
> > > > 
> > > > greg k-h
> > > 
> > > It is my first patch ever, can you guide me on how to resend the patch
> > > with the corrections.
> > > After adding the parentheses around the Macro, the Error was not showing
> > > up with the checkpatch.pl so I thought it corrected it.
> > > 
> > Did you build and run tests to make sure you change works?
> > 
> > Please go through the following to understand all about sending your first
> > patch.
> > 
> > https://wiki.linuxfoundation.org/lkmp/lkmp_getting_started
> > 
> > This should tell you the steps to follow before sending the patch.
> > 
> > thanks,
> > -- Shuah
> 
> 
> I built the driver and this change caused a compilation error. Sorry for
> sending a wrong patch.
> Please help me in solving the checkpatch.pl error.
> 
> ERROR: Macros with complex values should be enclosed in parentheses
> #2003: FILE: drivers/staging/media/bcm2048/radio-bcm2048.c:2003:
> +#define DEFINE_SYSFS_PROPERTY(prop, prop_type, mask, check)		\
> +property_write(prop, prop_type, mask, check)				\
> +property_read(prop, mask)						\
> +

How well do you understand C and how macros work with it?

Do you see anything wrong with this code?  What happens if you pass in
something "unusual" for one of those parameters?

Also, always remember that checkpatch.pl is a dumb perl script,
sometimes it is not correct, and may be ignored for some types of
things.

thanks,

greg k-h