On Thu, Nov 29, 2018 at 05:33:03PM +0000, Brian Starkey wrote: > This sounds very useful for ion, to avoid CPU cache maintenance as > long as the buffer stays in device-land. > > One question though: How would you determine "the last user to unmap" > to know when to do the final "make visible to CPU" step? I'd assume the user of the DMA API keeps track of it. E.g. dmabuf would be a pretty natural layer to implement common logic for this.
