SI(4) BSD Kernel Interfaces Manual SI(4)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 mother‐
boards (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 ALSOcd(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. Fur‐
ther progress has halted pending the availability of a machine for test‐
ing.
DMA, DMA completion interrupts, and reselection work fine on a Sun 4/260
with modern SCSI-II disks attached. There have been reports of reselec‐
tion 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.
BSD May 7, 1998 BSD
