I have been trying without luck to establish whether a DVD Drive has
DMA enable or enable it using hdparm -d1 /dev/scd0 (as mounted), but
all I get are the following type of error: "HDIO_SET_DMA failed:
Operation not permitted". Is DMA able to be set across USB, or is this
more likely to be that Angstrom doesn't have the right driver for my
IDE DVD?
AFAIK DMA is a feature of the ATA controller sitting on the PCI bus.
In your case the ATA controller is sitting on a USB bus with no direct
connection to the system RAM, so there's no sense speaking of DMA.
Regards,
Gyorgy