Re: [PATCH v2 1/2] drm: Add DRM_GEM_FOPS

[Rob Clark]

On Mon, Jun 6, 2022 at 11:56 PM Thomas Zimmermann <tzimmermann@xxxxxxx> wrote:
>
> Hi
>
> Am 06.06.22 um 21:54 schrieb Rob Clark:
> > From: Rob Clark <robdclark@xxxxxxxxxxxx>
> >
> > The DEFINE_DRM_GEM_FOPS() helper is a bit limiting if a driver wants to
> > provide additional file ops, like show_fdinfo().
> >
> > Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
> > ---
> >   include/drm/drm_gem.h | 26 ++++++++++++++++++--------
> >   1 file changed, 18 insertions(+), 8 deletions(-)
> >
> > diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
> > index 9d7c61a122dc..dc88d4a2cdf6 100644
> > --- a/include/drm/drm_gem.h
> > +++ b/include/drm/drm_gem.h
> > @@ -314,6 +314,23 @@ struct drm_gem_object {
> >       const struct drm_gem_object_funcs *funcs;
> >   };
> >
> > +/**
> > + * DRM_GEM_FOPS - Default drm GEM file operations
> > + *
> > + * This macro provides a shorthand for setting the GEM file ops in the
> > + * &file_operations structure.
>
> I would appreciate a reference to DEFINE_DRM_GEM_FOPS. Something along
> the lines of 'if all you need are the default ops, use DEFINE_DRM_GEM_FOPS'.
>
> > + */
> > +#define DRM_GEM_FOPS \
> > +     .open           = drm_open,\
> > +     .release        = drm_release,\
> > +     .unlocked_ioctl = drm_ioctl,\
> > +     .compat_ioctl   = drm_compat_ioctl,\
> > +     .poll           = drm_poll,\
> > +     .read           = drm_read,\
> > +     .llseek         = noop_llseek,\
> > +     .mmap           = drm_gem_mmap
> > +
> > +
>
> Only one empty line please.
>
> >   /**
> >    * DEFINE_DRM_GEM_FOPS() - macro to generate file operations for GEM drivers
> >    * @name: name for the generated structure
> > @@ -330,14 +347,7 @@ struct drm_gem_object {
> >   #define DEFINE_DRM_GEM_FOPS(name) \
> >       static const struct file_operations name = {\
> >               .owner          = THIS_MODULE,\
>
> Is there a specific reason why .owner is still set here? I suspect that
> DRM_GEM_FOPS is strictly for callback functions?

I was on the fence about that one, but it seemed better to not mix
"magic" and the callbacks.. but I could be convinced in either
direction

> In any case
>
> Acked-by: Thomas Zimmermann <tzimmermann@xxxxxxx>

thx, I'll fixup the other nits in v3.

>
> Best regards
> Thomas
>
> > -             .open           = drm_open,\
> > -             .release        = drm_release,\
> > -             .unlocked_ioctl = drm_ioctl,\
> > -             .compat_ioctl   = drm_compat_ioctl,\
> > -             .poll           = drm_poll,\
> > -             .read           = drm_read,\
> > -             .llseek         = noop_llseek,\
> > -             .mmap           = drm_gem_mmap,\
> > +             DRM_GEM_FOPS,\
> >       }
> >
> >   void drm_gem_object_release(struct drm_gem_object *obj);
>
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Maxfeldstr. 5, 90409 Nürnberg, Germany
> (HRB 36809, AG Nürnberg)
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