Re: [PATCH v1 2/2] drivers/gpu/drm: don't select DMA_CMA or CMA from aspeed or etnaviv

From: Arnd Bergmann
Date: Thu Apr 08 2021 - 09:19:42 EST


On Thu, Apr 8, 2021 at 2:50 PM Linus Walleij <linus.walleij@xxxxxxxxxx> wrote:
>
> On Thu, Apr 8, 2021 at 2:01 PM David Hildenbrand <david@xxxxxxxxxx> wrote:
>
> > > This is something you could do using a hidden helper symbol like
> > >
> > > config DRMA_ASPEED_GFX
> > > bool "Aspeed display driver"
> > > select DRM_WANT_CMA
> > >
> > > config DRM_WANT_CMA
> > > bool
> > > help
> > > Select this from any driver that benefits from CMA being enabled
> > >
> > > config DMA_CMA
> > > bool "Use CMA helpers for DRM"
> > > default DRM_WANT_CMA
> > >
> > > Arnd
> > >
> >
> > That's precisely what I had first, with an additional "WANT_CMA" -- but
> > looking at the number of such existing options (I was able to spot 1 !)
>
> If you do this it probably makes sense to fix a few other drivers
> Kconfig in the process. It's not just a problem with your driver.
> "my" drivers:
>
> drivers/gpu/drm/mcde/Kconfig
> drivers/gpu/drm/pl111/Kconfig
> drivers/gpu/drm/tve200/Kconfig
>
> certainly needs this as well, and pretty much anything that is
> selecting DRM_KMS_CMA_HELPER or
> DRM_GEM_CMA_HELPER "wants" DMA_CMA.

Are there any that don't select either of the helpers and
still want CMA? If not, it would be easy to just add

default DRM_KMS_CMA_HELPER || DRM_GEM_CMA_HELPER

and skipt the extra symbol.

Arnd