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

[Linus Walleij]

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.

Yours,
Linus Walleij