Re: [PATCH 06/13] drm/etnaviv: Use sychronized interface of the IOMMU-API

[Joerg Roedel]

On Thu, Aug 17, 2017 at 04:03:54PM +0200, Lucas Stach wrote:
> There is no IOMMU driver in use. Etnaviv just uses part of the IOMMU API
> to manage the GPU internal MMU, see
> drivers/gpu/drm/etnaviv/etnaviv_iommu.c

That looks like a very fragile construct, because it relies on internal
behavior of the iommu code that can change in the future.

I strongly suggest to either make etnaviv_iommu.c a real iommu driver an
move it to drivers/iommu, or (prefered by me) just call directly into
the map/unmap functions of this driver from the rest of the
etnaviv_iommu.c. I don't really see a reason why the IOMMU-API needs to
be used there as another layer of indirection.

Regards,

	Joerg