31st address line sometimes not used on EHCI/UHCI/OHCI

John-Mark Gurney gurney_j at resnet.uoregon.edu
Sun May 27 22:19:41 UTC 2007


Hans Petter Selasky wrote this message on Sun, May 27, 2007 at 22:35 +0200:
> I've got some reports back that some USB host controllers do not support 
> transferring memory from a location higher than 2GB.
> 
> What should we do about this?
> 
> Should we limit all USB DMA allocations to the lower 2GB of the memory?

No, a quirk table should be setup and pass the restriction to bus_dma
at tag initalization time when a broken controller is detected..

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."


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