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From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Wed, 22 Jun 2022 14:47:12 -0400
Message-ID: <CADnq5_MLUi5LL0cXFU=1m3r_TEWw=rTSXHm3V+6NYT_LfdmK+A@mail.gmail.com>
Subject: Re: [PATCH] drm/fourcc: fix integer type usage in uapi header
To:     Simon Ser <contact@emersion.fr>
Cc:     Carlos Llamas <cmllamas@google.com>,
        David Airlie <airlied@linux.ie>,
        Masahiro Yamada <masahiroy@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Maling list - DRI developers 
        <dri-devel@lists.freedesktop.org>,
        amd-gfx list <amd-gfx@lists.freedesktop.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Alex Deucher <alexander.deucher@amd.com>
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Precedence: bulk

Applied.  Thanks!

Alex

On Wed, Jun 22, 2022 at 3:02 AM Simon Ser <contact@emersion.fr> wrote:
>
> On Tuesday, June 21st, 2022 at 22:39, Carlos Llamas <cmllamas@google.com>=
 wrote:
>
> > Kernel uapi headers are supposed to use __[us]{8,16,32,64} types define=
d
> > by <linux/types.h> as opposed to 'uint32_t' and similar. See [1] for th=
e
> > relevant discussion about this topic. In this particular case, the usag=
e
> > of 'uint64_t' escaped headers_check as these macros are not being calle=
d
> > here. However, the following program triggers a compilation error:
> >
> >   #include <drm/drm_fourcc.h>
> >
> >   int main()
> >   {
> >       unsigned long x =3D AMD_FMT_MOD_CLEAR(RB);
> >       return 0;
> >   }
> >
> > gcc error:
> >   drm.c:5:27: error: =E2=80=98uint64_t=E2=80=99 undeclared (first use i=
n this function)
> >       5 |         unsigned long x =3D AMD_FMT_MOD_CLEAR(RB);
> >         |                           ^~~~~~~~~~~~~~~~~
> >
> > This patch changes AMD_FMT_MOD_{SET,CLEAR} macros to use the correct
> > integer types, which fixes the above issue.
> >
> >   [1] https://lkml.org/lkml/2019/6/5/18
> >
> > Fixes: 8ba16d599374 ("drm/fourcc: Add AMD DRM modifiers.")
> > Signed-off-by: Carlos Llamas <cmllamas@google.com>
>
> Reviewed-by: Simon Ser <contact@emersion.fr>
>
> Cc'ing Bas as well
>
> > ---
> >  include/uapi/drm/drm_fourcc.h | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourc=
c.h
> > index f1972154a594..0980678d502d 100644
> > --- a/include/uapi/drm/drm_fourcc.h
> > +++ b/include/uapi/drm/drm_fourcc.h
> > @@ -1444,11 +1444,11 @@ drm_fourcc_canonicalize_nvidia_format_mod(__u64=
 modifier)
> >  #define AMD_FMT_MOD_PIPE_MASK 0x7
> >
> >  #define AMD_FMT_MOD_SET(field, value) \
> > -     ((uint64_t)(value) << AMD_FMT_MOD_##field##_SHIFT)
> > +     ((__u64)(value) << AMD_FMT_MOD_##field##_SHIFT)
> >  #define AMD_FMT_MOD_GET(field, value) \
> >       (((value) >> AMD_FMT_MOD_##field##_SHIFT) & AMD_FMT_MOD_##field##=
_MASK)
> >  #define AMD_FMT_MOD_CLEAR(field) \
> > -     (~((uint64_t)AMD_FMT_MOD_##field##_MASK << AMD_FMT_MOD_##field##_=
SHIFT))
> > +     (~((__u64)AMD_FMT_MOD_##field##_MASK << AMD_FMT_MOD_##field##_SHI=
FT))
> >
> >  #if defined(__cplusplus)
> >  }
> > --
> > 2.37.0.rc0.104.g0611611a94-goog