'\" te
.\"  Copyright (c) 2006, Sun Microsystems, Inc.,  All Rights Reserved
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.TH SCSI_TRANSPORT 9F "Jan 16, 2006"
.SH NAME
scsi_transport \- request by a SCSI target driver to start a command
.SH SYNOPSIS
.nf
#include <sys/scsi/scsi.h>



\fBint\fR \fBscsi_transport\fR(\fBstruct scsi_pkt *\fR\fIpkt\fR);
.fi

.SH INTERFACE LEVEL
illumos DDI specific (illumos DDI).
.SH PARAMETERS
.ne 2
.na
\fB\fIpkt\fR\fR
.ad
.RS 7n
Pointer to a \fBscsi_pkt\fR(9S) structure.
.RE

.SH DESCRIPTION
Target drivers use \fBscsi_transport()\fR to request the host adapter driver to
transport a command to the \fBSCSI \fRtarget device specified by \fIpkt\fR. The
target driver must obtain resources for the packet using
\fBscsi_init_pkt\fR(9F) prior to calling this function. The packet may be
initialized using one of the \fBmakecom\fR(9F) functions.
\fBscsi_transport()\fR does not wait for the \fBSCSI\fR command to complete.
See \fBscsi_poll\fR(9F) for a description of polled \fBSCSI\fR commands. Upon
completion of the \fBSCSI\fR command the host adapter calls the completion
routine provided by the target driver in the \fBpkt_comp\fR member of the
\fBscsi_pkt\fR pointed to by \fIpkt\fR.
.SH RETURN VALUES
The \fBscsi_transport()\fR function returns:
.sp
.ne 2
.na
\fB\fBTRAN_ACCEPT\fR\fR
.ad
.RS 20n
The packet was accepted by the transport layer.
.RE

.sp
.ne 2
.na
\fB\fBTRAN_BUSY\fR\fR
.ad
.RS 20n
The packet could not be accepted because there was already a packet in progress
for this target/lun, the host adapter queue was full, or the target device
queue was full.
.RE

.sp
.ne 2
.na
\fB\fBTRAN_BADPKT\fR\fR
.ad
.RS 20n
The \fBDMA\fR count in the packet exceeded the \fBDMA\fR engine's maximum
\fBDMA\fR size.
.RE

.sp
.ne 2
.na
\fB\fBTRAN_FATAL_ERROR\fR\fR
.ad
.RS 20n
A fatal error has occurred in the transport layer.
.RE

.SH CONTEXT
The \fBscsi_transport()\fR function can be called from user, interrupt, or
kernel context.
.SH EXAMPLES
\fBExample 1 \fRUsing \fBscsi_transport()\fR
.sp
.in +2
.nf
if ((status = scsi_transport(rqpkt)) != TRAN_ACCEPT) {
      scsi_log(devp, sd_label, CE_WARN,
          "transport of request sense pkt fails (0x%x)\en", status);
}
.fi
.in -2

.SH SEE ALSO
.BR tran_start (9E),
.BR makecom (9F),
.BR scsi_init_pkt (9F),
.BR scsi_pktalloc (9F),
.BR scsi_poll (9F),
.BR scsi_pkt (9S)
.sp
.LP
\fIWriting Device Drivers\fR