1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>usb_get_status</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-string.html" title="usb_string"><link rel="next" href="API-usb-clear-halt.html" title="usb_clear_halt"></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_get_status</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-usb-string.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-clear-halt.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-usb-get-status"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>usb_get_status &#8212; 
2     issues a GET_STATUS call
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_get_status </b>(</code></td><td>struct usb_device * <var class="pdparam">dev</var>, </td></tr><tr><td>&#160;</td><td>int <var class="pdparam">type</var>, </td></tr><tr><td>&#160;</td><td>int <var class="pdparam">target</var>, </td></tr><tr><td>&#160;</td><td>void * <var class="pdparam">data</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1116236100"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>dev</code></em></span></dt><dd><p>
4     the device whose status is being checked
5    </p></dd><dt><span class="term"><em class="parameter"><code>type</code></em></span></dt><dd><p>
6     USB_RECIP_*; for device, interface, or endpoint
7    </p></dd><dt><span class="term"><em class="parameter"><code>target</code></em></span></dt><dd><p>
8     zero (for device), else interface or endpoint number
9    </p></dd><dt><span class="term"><em class="parameter"><code>data</code></em></span></dt><dd><p>
10     pointer to two bytes of bitmap data
11    </p></dd></dl></div></div><div class="refsect1"><a name="idp1116240732"></a><h2>Context</h2><p>
12   !in_interrupt ()
13</p></div><div class="refsect1"><a name="idp1116241308"></a><h2>Description</h2><p>
14   Returns device, interface, or endpoint status.  Normally only of
15   interest to see if the device is self powered, or has enabled the
16   remote wakeup facility; or whether a bulk or interrupt endpoint
17   is halted (<span class="quote">&#8220;<span class="quote">stalled</span>&#8221;</span>).
18   </p><p>
19
20   Bits in these status bitmaps are set using the SET_FEATURE request,
21   and cleared using the CLEAR_FEATURE request.  The <code class="function">usb_clear_halt</code>
22   function should be used to clear halt (<span class="quote">&#8220;<span class="quote">stall</span>&#8221;</span>) status.
23   </p><p>
24
25   This call is synchronous, and may not be used in an interrupt context.
26   </p><p>
27
28   Returns 0 and the status value in *<em class="parameter"><code>data</code></em> (in host byte order) on success,
29   or else the status code from the underlying <code class="function">usb_control_msg</code> call.
30</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-string.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-clear-halt.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">usb_string</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_clear_halt</span></td></tr></table></div></body></html>
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