<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 - [SKL] Black screen on 4.15-rc6 (DP link training error) [regression]"
href="https://bugs.freedesktop.org/show_bug.cgi?id=104451">104451</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[SKL] Black screen on 4.15-rc6 (DP link training error) [regression]
</td>
</tr>
<tr>
<th>Product</th>
<td>DRI
</td>
</tr>
<tr>
<th>Version</th>
<td>DRI git
</td>
</tr>
<tr>
<th>Hardware</th>
<td>x86-64 (AMD64)
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux (All)
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>major
</td>
</tr>
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<th>Component</th>
<td>DRM/Intel
</td>
</tr>
<tr>
<th>Assignee</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>direx@betriebsdirektor.de
</td>
</tr>
<tr>
<th>QA Contact</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>CC</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=136486" name="attach_136486" title="DP link training errors in dmesg with drm.debug=0x1e">attachment 136486</a> <a href="attachment.cgi?id=136486&action=edit" title="DP link training errors in dmesg with drm.debug=0x1e">[details]</a></span>
DP link training errors in dmesg with drm.debug=0x1e
I've just booted 4.15-rc6 and I am getting a black external screen (Thinkpad
L460 with Ultra Dock and external DP monitor). Stable Kernels (4.14 and older)
work just fine.
The dmesg is flooded with link training errors, so I was unable to capture a
full system log through SSH. The attached dmesg lines are the last link
training messages with drm.debug=0x1e. Thousands of these messages appear every
second.
The messages appear right when modesetting kicks in, before Wayland is
starting.
This is a major issue, as this is a regression which cause DP displays to fail.
My Configuration:
- Thinkpad L460 with Ultra Dock (contains a DP MST hub)
- External DP monitor connected to Ultra Dock
- Arch Linux
- Kernel 4.15-rc6
- Intel Core i5-6200U</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>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>