1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>usb_function_deactivate</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="USB Gadget API for Linux"><link rel="up" href="composite.html" title="Composite Device Framework"><link rel="prev" href="API-usb-add-function.html" title="usb_add_function"><link rel="next" href="API-usb-function-activate.html" title="usb_function_activate"></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_function_deactivate</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-usb-add-function.html">Prev</a>&#160;</td><th width="60%" align="center">Composite Device Framework</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-usb-function-activate.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-usb-function-deactivate"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>usb_function_deactivate &#8212; 
2     prevent function and gadget enumeration
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_function_deactivate </b>(</code></td><td>struct usb_function * <var class="pdparam">function</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1124414796"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>function</code></em></span></dt><dd><p>
4     the function that isn't yet ready to respond
5    </p></dd></dl></div></div><div class="refsect1"><a name="idp1124416388"></a><h2>Description</h2><p>
6   Blocks response of the gadget driver to host enumeration by
7   preventing the data line pullup from being activated.  This is
8   normally called during <em class="parameter"><code>bind</code></em>() processing to change from the
9   initial <span class="quote">&#8220;<span class="quote">ready to respond</span>&#8221;</span> state, or when a required resource
10   becomes available.
11   </p><p>
12
13   For example, drivers that serve as a passthrough to a userspace
14   daemon can block enumeration unless that daemon (such as an OBEX,
15   MTP, or print server) is ready to handle host requests.
16   </p><p>
17
18   Not all systems support software control of their USB peripheral
19   data pullups.
20   </p><p>
21
22   Returns zero on success, else negative errno.
23</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-add-function.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="composite.html">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API-usb-function-activate.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">usb_add_function</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_function_activate</span></td></tr></table></div></body></html>
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