.\"
.\" Copyright (c) 1994 Jordan Hubbard
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd August 18, 2020
.Dt BT 4
.Os
.Sh NAME
.Nm bt
.Nd Buslogic/Mylex MultiMaster SCSI host adapter driver
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following lines in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device isa"
.Cd "device scbus"
.Cd "device bt"
.Pp
In
.Pa /boot/device.hints :
.Cd hint.bt.0.at="isa"
.Cd hint.bt.0.port="0x330"
.Ed
.Sh DEPRECATION NOTICE
This driver is scheduled for removal prior to the release of
.Fx 13.0 .
.Sh DESCRIPTION
This driver provides access to the
.Tn SCSI
bus connected to a Buslogic/Mylex MultiMaster or compatible controller:
.Bd -ragged -offset indent
MultiMaster "W" Series Host Adapters:
.Bl -column "BT-956CD " "ISA " "Commands " "Description"
.Em "Adapter" Ta Em "Bus" Ta Em "Commands" Ta Em "Description"
BT-948	PCI	192	Ultra SCSI-3
BT-958	PCI	192	Wide Ultra SCSI-3
BT-958D	PCI	192	Wide Differential Ultra SCSI-3
.El
.Pp
MultiMaster "C" Series Host Adapters:
.Bl -column "BT-956CD " "ISA " "Commands " "Description"
.Em "Adapter" Ta Em "Bus" Ta Em "Commands" Ta Em "Description"
BT-946C	PCI	100	Fast SCSI-2
BT-956C	PCI	100	Wide Fast SCSI-2
BT-956CD	PCI	100	Wide Differential Fast SCSI-2
BT-445C	VLB	100	Fast SCSI-2
BT-545C	ISA	50	Fast SCSI-2
BT-540CF	ISA	50	Fast SCSI-2
.El
.Pp
MultiMaster "S" Series Host Adapters:
.Bl -column "BT-956CD " "ISA " "Commands " "Description"
.Em "Adapter" Ta Em "Bus" Ta Em "Commands" Ta Em "Description"
BT-445S	VLB	30	Fast SCSI-2
BT-545S	ISA	30	Fast SCSI-2
BT-542D	ISA	30	Differential Fast SCSI-2
BT-542B	ISA	30	SCSI-2 (542B revision H)
.El
.Pp
MultiMaster "A" Series Host Adapters:
.Bl -column "BT-956CD " "ISA " "Commands " "Description"
.Em "Adapter" Ta Em "Bus" Ta Em "Commands" Ta Em "Description"
BT-542B	ISA	30	SCSI-2 (542B revisions A - G)
.El
.Ed
.Pp
Tagged queueing is supported on 'W' series adapters, 'C' series adapters
with firmware of rev 4.42 and higher, and 'S' series adapters with firmware
of rev 3.35 and higher.
.Pp
Boards with certain firmware revisions may lock up under heavy load to
certain devices, especially if tagged queueing is used.
Should you encounter
a problem with your adapter, contact Mylex technical support and ensure you
have the latest firmware for your controller.
.Sh HARDWARE
The
.Nm
driver supports the following BusLogic MultiMaster
.Dq W ,
.Dq C ,
.Dq S ,
and
.Dq A
series and compatible SCSI host adapters:
.Pp
.Bl -bullet -compact
.It
BusLogic BT-445C
.It
BusLogic BT-445S
.It
BusLogic BT-540CF
.It
BusLogic BT-542B
.It
BusLogic BT-542B
.It
BusLogic BT-542D
.It
BusLogic BT-545C
.It
BusLogic BT-545S
.It
BusLogic/BusTek BT-640
.It
BusLogic BT-946C
.It
BusLogic BT-948
.It
BusLogic BT-956C
.It
BusLogic BT-956CD
.It
BusLogic BT-958
.It
BusLogic BT-958D
.It
Storage Dimensions SDC3211B / SDC3211F
.El
.Sh SEE ALSO
.Xr cd 4 ,
.Xr da 4 ,
.Xr sa 4 ,
.Xr scsi 4
.Sh HISTORY
The
.Nm
driver first appeared in the
.Bx 386
patch kit.
.Sh AUTHORS
.An -nosplit
.An Julian Elischer
wrote a driver for the Multimaster cards that appeared in the
.Bx 386
patch kit.
The driver was rewritten by
.An Justin T. Gibbs
to take advantage of new board features and work with the CAM SCSI framework in
.Fx 3.0 .
.Pp
Special thanks to
.An Leonard N. Zubkoff
for writing such a complete and well documented Mylex/BusLogic MultiMaster
driver for Linux.
Support in this driver for the wide range of MultiMaster
controllers and firmware revisions, with their otherwise undocumented quirks,
would not have been possible without his efforts.