1.\" $NetBSD: sc.4,v 1.1 2001/06/28 21:12:02 fredette Exp $ 2.\" 3.\" written from a reading of config files and driver source code 4.\" Erik E. Fair <fair@netbsd.org> 5.\" Matt Fredette <fredette@netbsd.org> 6.Dd June 28, 2001 7.Dt SC 4 8.Os 9.Sh NAME 10.Nm sc 11.Nd Sun Sun-2 SCSI bus host adaptor driver 12.Sh SYNOPSIS 13.Ss sun2 14.Cd "sc0 at mbmem0 addr 0x80000 ipl 2" 15.Cd "sc1 at mbmem0 addr 0x84000 ipl 2" 16.Ss sun2 and sun4 17.Cd "sc0 at vme0 addr 0x200000 irq 2 vec 0x40" 18.Sh DESCRIPTION 19The 20.Nm 21driver provides support for the 22Sun Microsystems 23.Qq Sun-2 24.Tn SCSI 25Bus Controller chipset found on various 26VME boards 27.Pq Sun part #s 501-1045, 501-1138, 501-1149, and 501-1167 28and on the 29.Qq Sun-2 SCSI/Serial 30.Pq Sun part # 501-1006 31Multibus board. 32.Pp 33All 34versions of this driver can be configured with a 35.Em flags 36directive in the 37.Xr config 8 38file. 39The values are bits in a bitfield, and are interpreted as follows: 40.Pp 41.Bl -tag -offset indent -compact -width 0x000ff 42.It 0x0ff 43Set bit (1<<target) to disable 44.Tn SCSI 45parity checking 46.It 0x100 47Set this bit to disable 48.Tn DMA 49interrupts (poll) 50.It 0x200 51Set this bit to disable 52.Tn DMA 53entirely (use PIO) 54.El 55.Pp 56For example: 57.Qq flags 0x1ff 58would disable 59.Tn DMA 60interrupts, and disable parity checking for targets 0-7. 61The 62.Qq target 63is the 64.Tn SCSI 65ID number of a particular device on a particular 66.Tn SCSI 67bus. 68.Sh BUGS 69This 70.Tn SCSI 71chipset is rumored to have bugs in its handling of 72.Tn SCSI 73parity, therefore it is recommended that you disable parity 74on all 75.Tn SCSI 76devices connected to this controller, and configure it with 77a 780x0ff 79value for its 80.Em flags 81directive in the 82.Xr config 8 83file. 84.Pp 85This 86chipset has no support for raising the 87.Tn ATN 88signal, so there is no way to ever schedule a 89.Tn MSG_OUT 90phase on the bus. Currently, the driver will ultimately 91reset the bus if this phase is ever requested by the upper 92layer 93.Tn SCSI 94driver. 95.Pp 96This chipset has no support for 97.Tn SCSI 98disconnect/reselect. This means that slow devices, 99such as tape drives, can hog, or 100.Qq lock up 101the SCSI bus. 102.Pp 103This driver has not been tested in combination with 104non-SCSI devices behind 105.Tn Emulex 106or 107.Tn Adaptec 108bridges, which are common in 109.Tn Sun 1102s and in 111.Tn Sun 112Shoebox-type configurations. 113These devices pre-date the 114.Tn SCSI-I 115spec, and might not behave the way the chipset code currently expects. 116.Sh SEE ALSO 117.Xr intro 4 , 118.Xr scsi 4 , 119.Xr sd 4 , 120.Xr st 4 , 121.Xr cd 4 , 122.Xr ch 4 123.Sh AUTHOR 124Matt Fredette, 125.Aq fredette@netbsd.org , 126.br 127David Jones, 128.br 129Gordon Ross 130.Aq gwr@netbsd.org , 131.br 132Adam Glass 133.Aq glass@netbsd.org , 134.br 135Jason R. Thorpe 136.Aq thorpej@netbsd.org . 137