Unrelenting testplan D25219

[Ian Lepore]

On Fri, 2020-06-12 at 18:49 +0200, Hans Petter Selasky wrote:
> On 2020-06-12 17:02, Robert Crowston wrote:
> > What is the physical address to which the xhci controller is
> > performing DMA? It needs to be in the lower 3 GB of the physical
> > address space.
> 
> The XHCI doesn't set any limits on the DMA location, but it easily
> can.
> 
> 

If the xhci controller's view of memory is limited to certain ranges,
then that should be reflected in the dmatag set up by its bus parent
who knows the range restrictions.  Nothing would need to change in the
xhci driver itself (assuming xhci uses bus_get_dma_tag() like it should
when creating its own tag(s)).

-- Ian