[PATCH] drm/amdkfd: fix build error with missing AMD_IOMMU_V2

[Arnd Bergmann]

On Mon, Mar 8, 2021 at 5:24 PM Felix Kuehling <felix.kuehling at amd.com> wrote:
>
> The driver build should work without IOMMUv2. In amdkfd/Makefile, we
> have this condition:
>
> ifneq ($(CONFIG_AMD_IOMMU_V2),)
> AMDKFD_FILES += $(AMDKFD_PATH)/kfd_iommu.o
> endif
>
> In amdkfd/kfd_iommu.h we define inline stubs of the functions that are
> causing your link-failures if IOMMU_V2 is not enabled:
>
> #if defined(CONFIG_AMD_IOMMU_V2_MODULE) || defined(CONFIG_AMD_IOMMU_V2)
> ... function declarations ...
> #else
> ... stubs ...
> #endif

Right, that is the problem I tried to explain in my patch description.

Should we just drop the 'imply' then and add a proper dependency like this?

      depends on DRM_AMDGPU && (X86_64 || ARM64 || PPC64)
      depends on AMD_IOMMU_V2=y || DRM_AMDGPU=m

I can send a v2 after some testing if you prefer this version.

        Arnd