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

From: David Hildenbrand
Date: Thu Apr 08 2021 - 12:44:40 EST


On 08.04.21 14:49, Linus Walleij 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:


:) I actually wanted to convert them to "depends on DMA_CMA" but ran into recursive dependencies ...

drivers/gpu/drm/mcde/Kconfig
drivers/gpu/drm/pl111/Kconfig
drivers/gpu/drm/tve200/Kconfig

I was assuming these are "real" dependencies. Will it also work without DMA_CMA?


certainly needs this as well, and pretty much anything that is
selecting DRM_KMS_CMA_HELPER or
DRM_GEM_CMA_HELPER "wants" DMA_CMA.

"wants" as in "desires to use but can life without" or "wants" as in "really needs it". ?

--
Thanks,

David / dhildenb