On Mon, Jun 27, 2005 at 06:48:06AM +1000, matthew green wrote:
> 
>    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.

I'm suggesting that we should create logical "bus" drivers to attach
these devices to.  They wouldn't actually _do_ anything but act as
a shim to set up bus_dma the right way; but they should be sufficient
for that, no?

-- 
 Thor Lancelot Simon	                                      tls@rek.tjls.com

"The inconsistency is startling, though admittedly, if consistency is to be
 abandoned or transcended, there is no problem."		- Noam Chomsky