NAME
si,
sw
- NCR 5380 SCSI bus host adaptor driver
SYNOPSIS
sun3
si0 at obio0 addr 0x140000 ipl 2
sun3 and sun3x
si0 at vme2 addr 0x200000 ipl 2 vect 0x40
si1 at vme2 addr 0x204000 ipl 2 vect 0x41
sun3/E
sebuf0 at vme2 addr 0x300000 ipl 2 vect 0x74 # and 0x75
sebuf1 at vme2 addr 0x340000 ipl 2 vect 0x76 # and 0x77
si* at sebuf?
sun4 and sun2
si0 at vme0 addr 0x200000 pri 2 vec 0x40
sun4/100
sw0 at obio0 addr 0x0a000000 level 3
DESCRIPTION
The
si
and
sw
"SCSI Weird
drivers provide support for the
NCR
5380
SCSI
Bus Controller (SBC) chip found on various Sun Microsystems
CPU
motherboards (obio), and on the
"Sun-3 VME SCSI
(Sun part # 501-1236)
board used in systems with
VME
bus.
sun3 and sun3x
The
sun3
and
sun3x
version of this driver can be configured with a
flags
directive in the
config(1)
file.
The values are bits in a bitfield, and are interpreted as follows:
- 0x000ff
-
Set bit (1<<target) to disable
SCSI
disconnect/reselect
- 0x0ff00
-
Set bit (1<<(target+8)) to disable
SCSI
parity checking
- 0x10000
-
Set this bit to disable
DMA
interrupts (poll)
- 0x20000
-
Set this bit to disable
DMA
entirely (use PIO)
For example:
"flags 0x1000f
would disable
DMA
interrupts, and disable disconnect/reselect for targets 0-3.
The
"target
is the
SCSI
ID number of a particular device on a particular
SCSI
bus.
sun4
The
sun4
version of this driver can also be configured with a
flags
directive in the
config(1)
file.
The values are bits in a bitfield, and are interpreted as follows:
- 0x01
-
Use
DMA
(may be polled)
- 0x02
-
Use
DMA
completion interrupts
- 0x04
-
Allow
SCSI
disconnect/reselect
For example:
"flags 0x07
would enable
DMA,
interrupts, and reselect.
By default,
DMA
is enabled in the
sun4
driver.
SEE ALSO
cd(4),
ch(4),
intro(4),
scsi(4),
sd(4),
st(4)
AUTHORS
David Jones,
Gordon Ross
<gwr@NetBSD.org>,
Adam Glass
<glass@NetBSD.org>,
Jason R. Thorpe
<thorpej@NetBSD.org>.
BUGS
The
VME
variant has a bit to enable or disable the
DMA
engine, but that bit also gates the interrupt line from the
NCR5380
(!!).
Therefore, in order to get any interrupt from the
NCR5380,
(i.e. for reselect) one must clear the
DMA
engine transfer count and then enable
DMA.
This has the further complication that you CAN NOT touch the
NCR5380
while the
DMA
enable bit is set, so we have to turn
DMA
back off before we even look at the
NCR5380.
Support for the Sun 4/100
sw
"SCSI Weird
is not complete.
DMA
works, but interrupts (and, thus, reselection) don't for reasons unknown.
Further progress has halted pending the availability of a machine for testing.
DMA,
DMA
completion interrupts, and reselection work fine on a Sun 4/260 with modern
SCSI-II
disks attached.
There have been reports of reselection failing on
Sun
Shoebox-type configurations where
there are multiple non-SCSI devices behind
Emulex
or
Adaptec
bridges.
These devices pre-date the
SCSI-I
spec, and might not behave the way the NCR5380 code expects.
For this reason, only
DMA
is enabled by default in the
sun4
driver.