On Sun, Jun 26, 2005 at 09:53:51PM +0200, Manuel Bouyer wrote:
   > 
   > Right now, bus_dma(9) because it only knows the limitations of the bus
   > (e.g. the 16MB limit for ISA, or 4GB limit for 32bit PCI).
   
   Why not change the attachments for devices with broken bus interfaces
   to hang them off a fake "bus" that enforces the relevant DMA restrictions?
   
   After all, logically that's precisely how they are: they aren't on PCI,
   exactly, they're on a broken-bus-interface-"bus" behind the PCI (from
   the CPU's perspective) that enforces restrictions that PCI doesn't have.


i didn't think it was possible for a non-bus (and thus MD) driver to
provide it's own bus_dma_tag_t.