Am Wednesday 28 January 2009 21:25:56 schrieb David Brownell: > Or to put it differently: without an IOMMU you're going to > need to do a lot of buffer copying regardless. Once 3.5K by > direct DMA from the first page (plus header), then seven via > bouce buffers, one more direct DMA, and the rest with bounce > buffers. Right? That depends on the scatter/gather ability of the hardware. If it can assemble a packet from two locations, you can cope without bounce buffers, on condition you are passed a number of blocks equal to a multitude of your packet size (or all of them) Perhaps it is time to revive to old "chain" member of struct usb and let hcds specify to usbcore how long a chain they can take. Regards Oliver -- 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
