1.\" $NetBSD: sc.4,v 1.7 2005/06/20 13:25:24 peter 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 1 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\*[Lt]\*[Lt]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 SEE ALSO 69.Xr cd 4 , 70.Xr ch 4 , 71.Xr intro 4 , 72.Xr scsi 4 , 73.Xr sd 4 , 74.Xr st 4 75.Sh AUTHORS 76.An Matt Fredette 77.Aq fredette@NetBSD.org , 78.An David Jones, 79.An Gordon Ross 80.Aq gwr@NetBSD.org , 81.An Adam Glass 82.Aq glass@NetBSD.org , 83.An Jason R. Thorpe 84.Aq thorpej@NetBSD.org . 85.Sh BUGS 86This 87.Tn SCSI 88chipset is rumored to have bugs in its handling of 89.Tn SCSI 90parity, therefore it is recommended that you disable parity 91on all 92.Tn SCSI 93devices connected to this controller, and configure it with 94a 950x0ff 96value for its 97.Em flags 98directive in the 99.Xr config 1 100file. 101.Pp 102This 103chipset has no support for raising the 104.Tn ATN 105signal, so there is no way to ever schedule a 106.Tn MSG_OUT 107phase on the bus. Currently, the driver will ultimately 108reset the bus if this phase is ever requested by the upper 109layer 110.Tn SCSI 111driver. 112.Pp 113This chipset has no support for 114.Tn SCSI 115disconnect/reselect. This means that slow devices, 116such as tape drives, can hog, or 117.Qq lock up 118the SCSI bus. 119.Pp 120This driver has not been tested in combination with 121non-SCSI devices behind 122.Tn Emulex 123or 124.Tn Adaptec 125bridges, which are common in 126.Tn Sun 1272s and in 128.Tn Sun 129Shoebox-type configurations. 130These devices pre-date the 131.Tn SCSI-I 132spec, and might not behave the way the chipset code currently expects. 133