1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>intel_logical_ring_begin</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="Linux DRM Developer's Guide"><link rel="up" href="ch04s03.html#idp1128337188" title="Logical Rings, Logical Ring Contexts and Execlists"><link rel="prev" href="API-intel-execlists-submission.html" title="intel_execlists_submission"><link rel="next" href="API-intel-logical-ring-cleanup.html" title="intel_logical_ring_cleanup"></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">intel_logical_ring_begin</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-intel-execlists-submission.html">Prev</a>&#160;</td><th width="60%" align="center">Logical Rings, Logical Ring Contexts and Execlists</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-intel-logical-ring-cleanup.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-intel-logical-ring-begin"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>intel_logical_ring_begin &#8212; 
2     prepare the logical ringbuffer to accept some commands
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">intel_logical_ring_begin </b>(</code></td><td>struct intel_ringbuffer * <var class="pdparam">ringbuf</var>, </td></tr><tr><td>&#160;</td><td>struct intel_context * <var class="pdparam">ctx</var>, </td></tr><tr><td>&#160;</td><td>int <var class="pdparam">num_dwords</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1128398124"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>ringbuf</code></em></span></dt><dd><p>
4     Logical ringbuffer.
5    </p></dd><dt><span class="term"><em class="parameter"><code>ctx</code></em></span></dt><dd><p>
6     -- undescribed --
7    </p></dd><dt><span class="term"><em class="parameter"><code>num_dwords</code></em></span></dt><dd><p>
8     number of DWORDs that we plan to write to the ringbuffer.
9    </p></dd></dl></div></div><div class="refsect1"><a name="idp1128401772"></a><h2>Description</h2><p>
10   The ringbuffer might not be ready to accept the commands right away (maybe it needs to
11   be wrapped, or wait a bit for the tail to be updated). This function takes care of that
12   and also preallocates a request (every workload submission is still mediated through
13   requests, same as it did with legacy ringbuffer submission).
14</p></div><div class="refsect1"><a name="idp1128402708"></a><h2>Return</h2><p>
15   non-zero if the ringbuffer is not ready to be written to.
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