mmap()

[Julian Elischer]

Kamal R. Prasad wrote:

>
> My usb device probably doesn't have a dma controller, so I don't think 
> the bulk pipe can use any memory allocated by bus_dma. [Pl. correct me 
> if Im wrong this].
> thanks
> -kamal
>
all USB devices use full scatter-gather DMA.  UHCI and OHCI are limitted 
I believe to 4GB of ram.
EHCI (USB2) has a 64 bit extension that allows all DMAs  of data to be 
64 bit addresses.
I don't know however which chips support the 64 bit extensions.