Re: [Outreachy kernel] [PATCH 2/2] media: zoran: replace bit shifts by BIT() macro

[Julia Lawall]

On Fri, 9 Apr 2021, Mitali Borkar wrote:

> On Thu, Apr 08, 2021 at 11:15:07PM +0200, Julia Lawall wrote:
> >
> >
> > On Fri, 9 Apr 2021, Mitali Borkar wrote:
> >
> > > Added #include <linux/bitops.h> and replaced bit shifts by BIT() macro.
> > > This BIT() macro from linux/bitops.h is used to define ZR36057_VFESPFR_* bitmasks.
> > > Use of macro is better and neater. It maintains consistency.
> > > Reported by checkpatch.
> > >
> > > Signed-off-by: Mitali Borkar <mitaliborkar810@xxxxxxxxx>
> > > ---
> > >  drivers/staging/media/zoran/zr36057.h | 10 ++++++----
> > >  1 file changed, 6 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/staging/media/zoran/zr36057.h b/drivers/staging/media/zoran/zr36057.h
> > > index a2a75fd9f535..93075459f910 100644
> > > --- a/drivers/staging/media/zoran/zr36057.h
> > > +++ b/drivers/staging/media/zoran/zr36057.h
> > > @@ -8,6 +8,8 @@
> > >  #ifndef _ZR36057_H_
> > >  #define _ZR36057_H_
> > >
> > > +#include <linux/bitops.h>
> > > +
> > >  /* Zoran ZR36057 registers */
> > >
> > >  #define ZR36057_VFEHCR          0x000	/* Video Front End, Horizontal Configuration Register */
> > > @@ -31,12 +33,12 @@
> > >  #define ZR36057_VFESPFR_VER_DCM          8
> > >  #define ZR36057_VFESPFR_DISP_MODE        6
> > >  #define ZR36057_VFESPFR_YUV422          (0 << 3)
> > > -#define ZR36057_VFESPFR_RGB888          (1 << 3)
> > > +#define ZR36057_VFESPFR_RGB888          BIT(3)
> >
> > Uniformity is generally considered to be more important than using BIT.
> > Having only a few constants defined using BIT is a bit strange.
> >
> Okay Ma'am. Can you please tell me on how to proceed now? I am not sure
> how to proceed.

I think that this code should just be left as is.

Checkpatch makes suggestions.  Its suggestions are not always appropriate
for the context.

julia

>
> > julia
> >
> > >  #define ZR36057_VFESPFR_RGB565          (2 << 3)
> > >  #define ZR36057_VFESPFR_RGB555          (3 << 3)
> > > -#define ZR36057_VFESPFR_ERR_DIF          (1 << 2)
> > > -#define ZR36057_VFESPFR_PACK24          (1 << 1)
> > > -#define ZR36057_VFESPFR_LITTLE_ENDIAN    (1 << 0)
> > > +#define ZR36057_VFESPFR_ERR_DIF          BIT(2)
> > > +#define ZR36057_VFESPFR_PACK24          BIT(1)
> > > +#define ZR36057_VFESPFR_LITTLE_ENDIAN    BIT(0)
> > >
> > >  #define ZR36057_VDTR            0x00c	/* Video Display "Top" Register */
> > >
> > > --
> > > 2.30.2
> > >
> > > --
> > > You received this message because you are subscribed to the Google Groups "outreachy-kernel" group.
> > > To unsubscribe from this group and stop receiving emails from it, send an email to outreachy-kernel+unsubscribe@xxxxxxxxxxxxxxxx.
> > > To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/ac8ec2b70ac2cc7c541c05a1d9a8db1fe79df793.1617912177.git.mitaliborkar810%40gmail.com.
> > >
>