deal with cheap CD-ROMs and other devices that do not appear to have
any way to enable parity generation. In the future, it might be nice
to have this configurable on a per-device basis with back-to-back
parity errors automatically disabling parity for the device. That
would require some MI changes.
* Handle unaligned and odd-length transfers.
This could probably be handled better in the future.
but is a marked improvement. This takes advantage of a pseudo-DMA hardware
hack of Apple's that exposes a 16-bit register that the Apple-designed
memory controller acts like a DMA controller and handshakes into or out
of the FIFO. Wierd.
(currently only CD-ROM drives on i386). The sys/dev/scsipi system provides 2
busses to which devices can attach (scsibus and atapibus). This needed to
change some include files and structure names in the low level scsi drivers.
second argument. The NuBus autoconfig code had to be reorganized as a
result of this, and looks much more like a directly-attached bus now.
These changes eliminate __BROKEN_INDIRECT_CONFIG.
instead of 0x400.
- Restructure interrupt handling for more performance--continue to
read/write data as long as the device keeps us in a data xfer phase.
There is still a lot of room for speed improvement here. Perhaps it
lies is speeding up the interrupt path in general?
some guesses for the machines that have two of these buggers (I don't have
such a machine). This driver is a copy of the sparc/alpha esp with a
minimum of changes--after we get it performing a bit more respectably,
we should see about re-normalizing the sources.
briggs