On Tue, 3 Feb 2009, David Vrabel wrote: > > Ah, but you're forgetting the possibile cases in which the controller > > doesn't support DMA. > > I don't think it's useful to speculate on possible hardware. If > hardware like this is produced then we can revisit this. What do you mean? Of course hardware like this exists, and Linux contains drivers for it. Otherwise there would be no reason for the code to be written the way it is. > For now, I would say that any HCD claiming sg-list support must always > support DMA. Why limit it? IMHO, all HCDs should have been written from the start to support discontiguous buffers. > It is unfortunate that neither myself nor Sarah can talk about the > specifics of the hardware where this sg list support is useful. It's useful in _all_ hardware, because any host controller can be connected to a mass-storage device. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
