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

[Lucas Stach]

Am Donnerstag, den 17.08.2017, 15:45 +0200 schrieb Joerg Roedel:
> Hi Lucas,
> 
> On Thu, Aug 17, 2017 at 03:32:38PM +0200, Lucas Stach wrote:
> > I don't think this is necessary. Etnaviv has managed and batched up TLB
> > flushes from day 1, as they don't happen through the MMU MMIO interface,
> > but through the GPU command stream.
> > 
> > So if my understanding of this series is correct, Etnaviv is just fine
> > with the changed semantics of the unsynchronized map/unmap calls.
> 
> This is not about any TLB on the GPU that could be flushed through the
> GPU command stream, but about the TLB in the IOMMU device. Or is this
> actually the same on this hardware? Which IOMMU-driver is use there?

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

Regards,
Lucas