1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>usb_interrupt_msg</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="The Linux-USB Host Side API"><link rel="up" href="usbcore.html" title="Chapter&#160;5.&#160;USB Core APIs"><link rel="prev" href="API-usb-control-msg.html" title="usb_control_msg"><link rel="next" href="API-usb-bulk-msg.html" title="usb_bulk_msg"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span class="phrase">usb_interrupt_msg</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-usb-control-msg.html">Prev</a>&#160;</td><th width="60%" align="center">Chapter&#160;5.&#160;USB Core APIs</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-usb-bulk-msg.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-usb-interrupt-msg"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>usb_interrupt_msg &#8212; 
2     Builds an interrupt urb, sends it off and waits for completion
3 </p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">int <b class="fsfunc">usb_interrupt_msg </b>(</code></td><td>struct usb_device * <var class="pdparam">usb_dev</var>, </td></tr><tr><td>&#160;</td><td>unsigned int <var class="pdparam">pipe</var>, </td></tr><tr><td>&#160;</td><td>void * <var class="pdparam">data</var>, </td></tr><tr><td>&#160;</td><td>int <var class="pdparam">len</var>, </td></tr><tr><td>&#160;</td><td>int * <var class="pdparam">actual_length</var>, </td></tr><tr><td>&#160;</td><td>int <var class="pdparam">timeout</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1116134996"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>usb_dev</code></em></span></dt><dd><p>
4     pointer to the usb device to send the message to
5    </p></dd><dt><span class="term"><em class="parameter"><code>pipe</code></em></span></dt><dd><p>
6     endpoint <span class="quote">&#8220;<span class="quote">pipe</span>&#8221;</span> to send the message to
7    </p></dd><dt><span class="term"><em class="parameter"><code>data</code></em></span></dt><dd><p>
8     pointer to the data to send
9    </p></dd><dt><span class="term"><em class="parameter"><code>len</code></em></span></dt><dd><p>
10     length in bytes of the data to send
11    </p></dd><dt><span class="term"><em class="parameter"><code>actual_length</code></em></span></dt><dd><p>
12     pointer to a location to put the actual length transferred
13     in bytes
14    </p></dd><dt><span class="term"><em class="parameter"><code>timeout</code></em></span></dt><dd><p>
15     time in msecs to wait for the message to complete before
16     timing out (if 0 the wait is forever)
17    </p></dd></dl></div></div><div class="refsect1"><a name="idp1116141892"></a><h2>Context</h2><p>
18   !in_interrupt ()
19</p></div><div class="refsect1"><a name="idp1116142468"></a><h2>Description</h2><p>
20   This function sends a simple interrupt message to a specified endpoint and
21   waits for the message to complete, or timeout.
22   </p><p>
23
24   Don't use this function from within an interrupt context, like a bottom half
25   handler.  If you need an asynchronous message, or need to send a message
26   from within interrupt context, use <code class="function">usb_submit_urb</code> If a thread in your
27   driver uses this call, make sure your <code class="function">disconnect</code> method can wait for it to
28   complete.  Since you don't have a handle on the URB used, you can't cancel
29   the request.
30</p></div><div class="refsect1"><a name="idp1116144348"></a><h2>Return</h2><p>
31   If successful, 0. Otherwise a negative error number. The number of actual
32   bytes transferred will be stored in the <em class="parameter"><code>actual_length</code></em> parameter.
33</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-usb-control-msg.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="usbcore.html">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API-usb-bulk-msg.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">usb_control_msg</span>&#160;</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">&#160;<span class="phrase">usb_bulk_msg</span></td></tr></table></div></body></html>
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