On Wed, May 24, 2017 at 07:01:42PM +0100, Jean-Philippe Brucker wrote: > * TLB invalidation by range is batched and committed with a single sync. > Batching ATC invalidation is inconvenient, endpoints limit the number of > inflight invalidations. We'd have to count the number of invalidations > queued and send a sync periodically. In addition, I suspect we always > need a sync between TLB and ATC invalidation for the same page. This sounds like the number of outstanding ATS invalidations is not managed by the SMMU hardware, is that right? Joerg