gpu: drm_fb_cma_helper.c:46: undefined reference to `drm_gem_fb_get_obj'

[Arnd Bergmann]

On Wed, Oct 27, 2021 at 8:26 AM Randy Dunlap <rdunlap at infradead.org> wrote:
> On 10/26/21 11:19 PM, Arnd Bergmann wrote:
> > On Wed, Oct 27, 2021 at 2:58 AM Randy Dunlap <rdunlap at infradead.org> wrote:

> > This trivial change makes it all build:
> >
> > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> > index c08860db2520..699f434ce813 100644
> > --- a/drivers/gpu/drm/Kconfig
> > +++ b/drivers/gpu/drm/Kconfig
> > @@ -218,7 +218,7 @@ config DRM_GEM_CMA_HELPER
> >            Choose this if you need the GEM CMA helper functions
> >
> >   config

> > -       bool
> > +       tristate
> >          depends on DRM
> >          select DRM_GEM_CMA_HELPER
> >          help
> >
> > but this needs some more testing to make sure it doesn't add
> > any other regressions.
> >
> > Interestingly, I never hit the problem in randconfig testing since
> > there is always some '=y' driver that selects DRM_KMS_HELPER.
>
> Thomas had posted a patch that also fixes the problem.
> Somehow I missed seeing that the first time around.

Ah right, I missed that as well. That patch seems reasonable
to me, but I think we may want both of them in this case, as
it does not address DRM_GEM_CMA_HELPER being set to =y
when it is only used from modules.

       Arnd