At 8:48 Uhr -0800 17.1.2006, Chuck Silvers wrote:
>does anyone know what problems still exist with the sbc driver that
>would prevent us from switching to that and getting rid of the
>mac68k-specific ncrscsi driver?

Folklore has it that there are SCSI devices that work with one but not the
other, or vice versa (or none, like a Sun branded Seagate 420 MB disk I
have around).

> the MI driver is 50% faster and uses 1/3 less CPU time than the MD driver.

Is it? Which machine, which disk, which benchmark? You are aware that a
busy NetBSD/mac68k loses time so badly that any benchmark data is to be
taken with a spoon of salt?  ;)

Actually, folklore has it that ncrscsi is faster than sbc...

>also, does anyone know why the GENERICSBC config only turns on PDMA
>and not disconnects or interrupts?  I tried turning them on an it
>worked for me.

Again, which machine, which disk? To give an example, the IIsi that is
la.causeuse.org has

# SBC_PDMA      0x01    /* Use PDMA for polled transfers */
# SBC_INTR      0x02    /* Allow SCSI IRQ/DRQ interrupts */
# SBC_RESELECT  0x04    /* Allow disconnect/reselect */
sbc0    at obio? flags 0x1              # MI SCSI NCR 5380

for a DEC 1G disk that originally came with a Sun IPX. I tried at the time,
but nothing else worked. Quantum disks, OTOH, usually play nice with
ncrscsi.

It's a pity we didn't collect data when MacBSD users were still frequent;
but there _was_ a reason for keeping both drivers, and the driver code
hasn't seen significant change for many years.

Allen Briggs (ncrscsi) and Scott reynolds (sbc) may have more to say.

My 2 Cent,

	hauke


--
"It's never straight up and down"     (DEVO)