Re: [PATCH] drivers: gpu: Fix warning using plain integer as NULL

[Abhinav Singh <singhabhinav9051571833@xxxxxxxxx>]

On 11/6/23 16:53, Jani Nikula wrote:
> On Fri, 03 Nov 2023, Abhinav Singh <singhabhinav9051571833@xxxxxxxxx> wrote:
> > sparse static analysis tools generate a warning with this message
> > "Using plain integer as NULL pointer". In this case this warning is
> > being shown because we are trying to intialize a pointer to NULL using
> > integer value 0.
> >
> > Signed-off-by: Abhinav Singh <singhabhinav9051571833@xxxxxxxxx>
> > ---
> >   drivers/gpu/drm/radeon/clearstate_evergreen.h | 8 ++++----
> >   1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/radeon/clearstate_evergreen.h b/drivers/gpu/drm/radeon/clearstate_evergreen.h
> > index 63a1ffbb3ced..3b645558f133 100644
> > --- a/drivers/gpu/drm/radeon/clearstate_evergreen.h
> > +++ b/drivers/gpu/drm/radeon/clearstate_evergreen.h
> > @@ -1049,7 +1049,7 @@ static const struct cs_extent_def SECT_CONTEXT_defs[] =
> >       {SECT_CONTEXT_def_5, 0x0000a29e, 5 },
> >       {SECT_CONTEXT_def_6, 0x0000a2a5, 56 },
> >       {SECT_CONTEXT_def_7, 0x0000a2de, 290 },
> > -    { 0, 0, 0 }
> > +    { NULL, 0, 0 }
>
> Random drive-by comment:
>
> I'd just use {} as the sentinel.
>
> BR,
> Jani.
>
> >   };
> >   static const u32 SECT_CLEAR_def_1[] =
> >   {
> > @@ -1060,7 +1060,7 @@ static const u32 SECT_CLEAR_def_1[] =
> >   static const struct cs_extent_def SECT_CLEAR_defs[] =
> >   {
> >       {SECT_CLEAR_def_1, 0x0000ffc0, 3 },
> > -    { 0, 0, 0 }
> > +    { NULL, 0, 0 }
> >   };
> >   static const u32 SECT_CTRLCONST_def_1[] =
> >   {
> > @@ -1070,11 +1070,11 @@ static const u32 SECT_CTRLCONST_def_1[] =
> >   static const struct cs_extent_def SECT_CTRLCONST_defs[] =
> >   {
> >       {SECT_CTRLCONST_def_1, 0x0000f3fc, 2 },
> > -    { 0, 0, 0 }
> > +    { NULL, 0, 0 }
> >   };
> >   static const struct cs_section_def evergreen_cs_data[] = {
> >       { SECT_CONTEXT_defs, SECT_CONTEXT },
> >       { SECT_CLEAR_defs, SECT_CLEAR },
> >       { SECT_CTRLCONST_defs, SECT_CTRLCONST },
> > -    { 0, SECT_NONE }
> > +    { NULL, SECT_NONE }
> >   };
> > --
> > 2.39.2
Hi, Thanks for dropping by and the suggestion. I thought of using NULL 
instead of {} is because, first the warning itself says that 0 is used 
to intialize pointers with NULL, and second due this link 
https://www.spinics.net/lists/linux-sparse/msg10066.html where linus is 
talking about not using 0 NULL intialization of pointer variable and he 
thinks this is a legitimate issue and not some false positive