'\" te
.\"  Copyright (c) 2003, Sun Microsystems, Inc.,  All Rights Reserved
.TH ldi_aread 9F "3 June 2003" "SunOS 5.11" "Kernel Functions for Drivers"
.SH NAME
ldi_aread, ldi_awrite \- Issue an asynchronous read or write request to a device
.SH SYNOPSIS
.LP
.nf
#include <sys/sunldi.h>

\fB\fR\fBint\fR ldi_aread(\fBldi_handle_t\fR \fIlh\fR, \fB struct aio_req *\fR\fIaio_reqp\fR, \fBcred_t *\fR\fIcr\fR);
.fi

.LP
.nf
\fBint\fR \fB ldi_awrite\fR(\fBldi_handle_t\fR \fIlh\fR, \fB struct aio_req *\fR\fIaio_reqp\fR, \fBcred_t *\fR\fIcr\fR);
.fi

.SH PARAMETERS
.sp
.ne 2
.mk
.na
\fB\fIlh\fR \fR
.ad
.RS 13n
.rt  
Layered handle.
.RE

.sp
.ne 2
.mk
.na
\fB\fIcr\fR \fR
.ad
.RS 13n
.rt  
Pointer to a credential structure.
.RE

.sp
.ne 2
.mk
.na
\fB\fIaio_reqp\fR \fR
.ad
.RS 13n
.rt  
Pointer to the \fBaio_req(9S)\fR structure that describes where the data is to be stored or obtained from.
.RE

.SH DESCRIPTION
.sp
.LP
The \fBldi_awrite()\fR function passes an asynchronous write request to a device entry point specified by the layered handle. This operation is supported for block and character devices.
.sp
.LP
The \fBldi_aread()\fR function passes an asynchronous read request to a device entry point specified by the layered handle. This operation is supported for block and character devices.
.SH RETURN VALUES
.sp
.LP
The \fBldi_awrite()\fR and \fBldi_aread()\fR functions return \fB0\fR upon success. If a failure occurs before the request is passed on to the device, the possible return values are shown below. Otherwise any other error number may be returned by the device.
.sp
.ne 2
.mk
.na
\fBEINVAL\fR
.ad
.RS 11n
.rt  
Invalid input parameters.
.RE

.sp
.ne 2
.mk
.na
\fBENOTSUP\fR
.ad
.RS 11n
.rt  
Operation is not supported for this device.
.RE

.SH CONTEXT
.sp
.LP
These functions may be called from user context.