'\" te
.\"  Copyright (c) 2006, Sun Microsystems, Inc.,  All Rights Reserved
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.TH SCSI_RESET 9F "Jan 16, 2006"
.SH NAME
scsi_reset \- reset a SCSI bus or target
.SH SYNOPSIS
.nf
#include <sys/scsi/scsi.h>



\fBint\fR \fBscsi_reset\fR(\fBstruct scsi_address *\fR\fIap\fR, \fBint\fR \fIlevel\fR);
.fi

.SH INTERFACE LEVEL
illumos DDI specific (illumos DDI).
.SH PARAMETERS
.ne 2
.na
\fB\fIap\fR\fR
.ad
.RS 9n
Pointer to the \fBscsi_address\fR structure.
.RE

.sp
.ne 2
.na
\fB\fIlevel\fR\fR
.ad
.RS 9n
The level of reset required.
.RE

.SH DESCRIPTION
The \fBscsi_reset()\fR function asks the host adapter driver to reset the
\fBSCSI \fRbus or a \fBSCSI \fRtarget as specified by \fIlevel\fR. If
\fIlevel\fR equals \fBRESET_ALL\fR, the \fBSCSI\fR bus is reset. If it equals
\fBRESET_TARGET\fR, \fIap\fR is used to determine the target to be reset. If it
equals \fBRESET_LUN\fR, \fIap\fR is used to determine the logical unit to be
reset.
.sp
.LP
When given the \fBRESET_LUN\fR level, \fBscsi_reset()\fR can return failure if
the \fBLOGICAL UNIT RESET\fR message is not supported by the target device, or
if the underlying HBA driver does not implement the ability to issue a
\fBLOGICAL UNIT RESET\fR message.
.sp
.LP
Note that, at the point when \fBscsi_reset()\fR resets the logical unit (case
\fBRESET_LUN\fR), or the target (case \fBRESET_TARGET\fR), or the bus (case
\fBRESET_ALL\fR), there might be one or more command packets outstanding. That
is, packets have been passed to \fBscsi_transport()\fR, and queued or possibly
transported, but the commands have not been completed and the target completion
routine has not been called for those packets.
.sp
.LP
The successful call to \fBscsi_reset()\fR has the side effect that any such
commands currently outstanding are aborted, at which point the packets are
marked with \fBpkt_reason\fR set to \fBCMD_RESET\fR, and the appropriate bit --
either \fBSTAT_BUS_RESET\fR or \fBSTAT_DEV_RESET\fR -- is set in
\fBpkt_statistics\fR. Once thus appropriately marked, the aborted command
packets are passed to the target driver command completion routine.
.sp
.LP
Also note that, at the moment that a thread executing \fBscsi_reset()\fR
actually resets the target or the bus, it is possible that a second thread may
have already called \fBscsi_transport()\fR, but not yet queued or transported
its command. In this case the HBA will not yet have received the second
thread's packet and this packet will not be aborted.
.SH RETURN VALUES
The \fBscsi_reset()\fR function returns:
.sp
.ne 2
.na
\fB\fB1\fR\fR
.ad
.RS 5n
Upon success.
.RE

.sp
.ne 2
.na
\fB\fB0\fR\fR
.ad
.RS 5n
Upon failure.
.RE

.SH CONTEXT
The \fBscsi_reset()\fR function can be called from user, interrupt, or kernel
context.
.SH SEE ALSO
.BR tran_reset (9E),
.BR tran_reset_notify (9E),
.BR scsi_abort (9F)
.sp
.LP
\fIWriting Device Drivers\fR