--- Julian Elischer <[EMAIL PROTECTED]> wrote: > > > 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. > So how does one use bus_dma within the USB framework? The API exists, but I don't think any of the src code in src/sys/dev/usb actually uses bus_dma. Oh btw -my data transfer is < 100K, so the 64-bit thing is not an issue.
regards -kamal > > > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
