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      <base href="https://bugs.freedesktop.org/" />
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Blank screen and dmesg errors with two external monitors"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=93208">93208</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Blank screen and dmesg errors with two external monitors
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>DRI
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>XOrg 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>DRM/Intel
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>intel-gfx-bugs@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>bartolinidb@gmail.com
          </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>I am on a Thinkpad T450, if I connect a single external monitor, either via
miniDP or VGA, everything works fine.
If I connect both monitors, all output disappears and the only way to restore
is to go back to a text console and restart the display manager.

In dmesg, I get a lot of these messages:

[drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!

I found other bugs that report the same error message, but they seem to be
triggered by different conditions.

The two monitor used to work on a previous kernel (I'm not sure what version,
probably before 4.2).

Additional information follows:

$ uname -a
Linux davide 4.4.0-040400rc3-generic #201511300321 SMP Mon Nov 30 03:23:36 UTC
2015 x86_64 x86_64 x86_64 GNU/Linux

$ lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation Broadwell-U Integrated
Graphics (rev 09)

$ lsmod | grep i915
i915                 1204224  9
i2c_algo_bit           16384  1 i915
drm_kms_helper        135168  1 i915
drm                   360448  10 i915,drm_kms_helper
video                  40960  2 i915,thinkpad_acpi</pre>
        </div>
      </p>
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