We have several Quantum Fireball IDE drives. The product literature for
these drives says:

    The Fast ATA-2 interface on Quantum Fireball TM drives supports
    local-bus AT Programmed Input/Output (PIO) Mode 4 operation, and
    Multiword Direct Memory Access (DMA) Mode 2 interface protocols.

>From a look at wd.c, it seems like there is support for DMA in the
driver, but when I boot with one of these disks, I get:

    wd0 at wdc0 drive 0: 2014MB, 4092 cyl, 16 head, 63 sec, 512 bytes/sec <QUANTUM FIREBALL_TM2100A>
    wd0: using 16-sector 16-bit pio transfers, lba addressing

This implies that one of the following isn't true:

	if ((wd->sc_params.wdp_capabilities & WD_CAP_DMA) != 0 &&
	    wdc->sc_drq != DRQUNK)

Is there something else I need to do to make this work? (like, telling
it a drq in the kernel config file, for example? If so, which one?) (And
more importantly, if I get it working will the CPU actually be free to
do other stuff while the transfers are taking place?