On Tue, 11 Jun 2013, Thomas Pugliese wrote: > This patch adds support for scatter gather DMA to the wire adapter and > updates the HWA to advertise support for SG transfers. This allows the > block layer to submit transfer requests to the HWA HC without first > breaking them up into PAGE_SIZE requests. While I do not really understand what is going on here, it nevertheless seems very peculiar. To begin with, whether or not the block layer breaks up transfers into PAGE_SIZE requests has no connection with SG. For another thing, the patch has the HCD creating an SG list. That's not how things work -- the HCD _receives_ the SG list attached to an URB. I'm not sure what problem this patch is intended to solve. Can you explain in more detail? 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