1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>drm_atomic_helper_check_modeset</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="ch02s05.html#idp1125061196" title="Atomic Modeset Helper Functions Reference"><link rel="prev" href="API-drm-atomic-crtc-state-for-each-plane.html" title="drm_atomic_crtc_state_for_each_plane"><link rel="next" href="API-drm-atomic-helper-check-planes.html" title="drm_atomic_helper_check_planes"></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">drm_atomic_helper_check_modeset</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-drm-atomic-crtc-state-for-each-plane.html">Prev</a>&#160;</td><th width="60%" align="center">Atomic Modeset Helper Functions Reference</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-drm-atomic-helper-check-planes.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-drm-atomic-helper-check-modeset"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>drm_atomic_helper_check_modeset &#8212; 
2  validate state object for modeset changes
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">drm_atomic_helper_check_modeset </b>(</code></td><td>struct drm_device * <var class="pdparam">dev</var>, </td></tr><tr><td>&#160;</td><td>struct drm_atomic_state * <var class="pdparam">state</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1125094148"></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     DRM device
5    </p></dd><dt><span class="term"><em class="parameter"><code>state</code></em></span></dt><dd><p>
6     the driver state object
7    </p></dd></dl></div></div><div class="refsect1"><a name="idp1125096764"></a><h2>Description</h2><p>
8   Check the state object to see if the requested state is physically possible.
9   This does all the crtc and connector related computations for an atomic
10   update. It computes and updates crtc_state-&gt;mode_changed, adds any additional
11   connectors needed for full modesets and calls down into -&gt;mode_fixup
12   functions of the driver backend.
13</p></div><div class="refsect1"><a name="idp1125097772"></a><h2>IMPORTANT</h2><p>
14   </p><p>
15
16   Drivers which update -&gt;mode_changed (e.g. in their -&gt;atomic_check hooks if a
17   plane update can't be done without a full modeset) _must_ call this function
18   afterwards after that change. It is permitted to call this function multiple
19   times for the same update, e.g. when the -&gt;atomic_check functions depend upon
20   the adjusted dotclock for fifo space allocation and watermark computation.
21   </p><p>
22
23   RETURNS
24   Zero for success or -errno
25</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-drm-atomic-crtc-state-for-each-plane.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="ch02s05.html#idp1125061196">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API-drm-atomic-helper-check-planes.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">drm_atomic_crtc_state_for_each_plane</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">drm_atomic_helper_check_planes</span></td></tr></table></div></body></html>
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