<html>
<head>
<base href="https://bugs.freedesktop.org/">
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [GEN8+] Hang when discarding a fragment if dual source blending is enabled but shader doesn't support it"
href="https://bugs.freedesktop.org/show_bug.cgi?id=107088">107088</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[GEN8+] Hang when discarding a fragment if dual source blending is enabled but shader doesn't support it
</td>
</tr>
<tr>
<th>Product</th>
<td>Mesa
</td>
</tr>
<tr>
<th>Version</th>
<td>git
</td>
</tr>
<tr>
<th>Hardware</th>
<td>Other
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<th>Component</th>
<td>Drivers/DRI/i965
</td>
</tr>
<tr>
<th>Assignee</th>
<td>intel-3d-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>danylo.piliaiev@gmail.com
</td>
</tr>
<tr>
<th>QA Contact</th>
<td>intel-3d-bugs@lists.freedesktop.org
</td>
</tr></table>
<p>
<div>
<pre>The hang is reproducible under the next conditions
- Have blending enabled and use GL_SRC1_COLOR in blend function
- Have depth test enabled
- Have fragment shader which doesn't have second color output and discards
fragments
- Draw something with this shader
- Hang will occur
The hang was found in Unigine Heaven 4.0 running in dx11 mode under wine during
the investigation of the bug
<a class="bz_bug_link
bz_status_NEW "
title="NEW - [SKL] Unigine Heaven 4.0 fails to GPU hangs"
href="show_bug.cgi?id=103556">https://bugs.freedesktop.org/show_bug.cgi?id=103556</a>. I believe this two hangs
are separate issues since one in the original bug seems to happened with native
Unigine version and doesn't happen anymore.
The situation when dual color blending is enabled but shader doesn't support it
is undefined as stated in documentation (vol.7 3D-Media-GPGPU):
"If SRC1 is included in a src/dst blend factor and a DualSource RT Write
message is not used, results are UNDEFINED. (This reflects the same restriction
in DX APIs, where undefined results are produced if “o1” is not written by a PS
– there are no default values defined). If SRC1 is not included in a src/dst
blend factor, dual source blending must be disabled."</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the QA Contact for the bug.</li>
<li>You are the assignee for the bug.</li>
</ul>
</body>
</html>