'\" t
.\"     Title: usb_control_msg
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
.\"      Date: January 2017
.\"    Manual: USB Core APIs
.\"    Source: Kernel Hackers Manual 4.8.15
.\"  Language: English
.\"
.TH "USB_CONTROL_MSG" "9" "January 2017" "Kernel Hackers Manual 4\&.8\&." "USB Core APIs"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
usb_control_msg \- Builds a control urb, sends it off and waits for completion
.SH "SYNOPSIS"
.HP \w'int\ usb_control_msg('u
.BI "int usb_control_msg(struct\ usb_device\ *\ " "dev" ", unsigned\ int\ " "pipe" ", __u8\ " "request" ", __u8\ " "requesttype" ", __u16\ " "value" ", __u16\ " "index" ", void\ *\ " "data" ", __u16\ " "size" ", int\ " "timeout" ");"
.SH "ARGUMENTS"
.PP
\fIdev\fR
.RS 4
pointer to the usb device to send the message to
.RE
.PP
\fIpipe\fR
.RS 4
endpoint
\(lqpipe\(rq
to send the message to
.RE
.PP
\fIrequest\fR
.RS 4
USB message request value
.RE
.PP
\fIrequesttype\fR
.RS 4
USB message request type value
.RE
.PP
\fIvalue\fR
.RS 4
USB message value
.RE
.PP
\fIindex\fR
.RS 4
USB message index value
.RE
.PP
\fIdata\fR
.RS 4
pointer to the data to send
.RE
.PP
\fIsize\fR
.RS 4
length in bytes of the data to send
.RE
.PP
\fItimeout\fR
.RS 4
time in msecs to wait for the message to complete before timing out (if 0 the wait is forever)
.RE
.SH "CONTEXT"
.PP
!in_interrupt ()
.SH "DESCRIPTION"
.PP
This function sends a simple control message to a specified endpoint and waits for the message to complete, or timeout\&.
.PP
Don\*(Aqt use this function from within an interrupt context, like a bottom half handler\&. If you need an asynchronous message, or need to send a message from within interrupt context, use
\fBusb_submit_urb\fR\&. If a thread in your driver uses this call, make sure your
\fBdisconnect\fR
method can wait for it to complete\&. Since you don\*(Aqt have a handle on the URB used, you can\*(Aqt cancel the request\&.
.SH "RETURN"
.PP
If successful, the number of bytes transferred\&. Otherwise, a negative error number\&.
.SH "COPYRIGHT"
.br