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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 - [bisected]X segfaults during sddm start up"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=94799">94799</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>[bisected]X segfaults during sddm start up
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>xorg
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>git
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>Other
          </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>Driver/AMDgpu
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>xorg-driver-ati@lists.x.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>farmboy0+freedesktop@googlemail.com
          </td>
        </tr>

        <tr>
          <th>QA Contact</th>
          <td>xorg-team@lists.x.org
          </td>
        </tr></table>
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        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=122680" name="attach_122680" title="Xorg.log">attachment 122680</a> <a href="attachment.cgi?id=122680&action=edit" title="Xorg.log">[details]</a></span>
Xorg.log

With xf86-video-amdgpu git I cannot start the sddm login manager anymore.
Reverting the driver back to 1.0.1 fixes the problem.
Bisecting shows the following commit as the guilty party:

commit df60c635e1e632233de9dd4b01d63c2b963003f8
Author: Michel Dänzer <<a href="mailto:michel.daenzer@amd.com">michel.daenzer@amd.com</a>>
Date:   Wed Feb 24 17:06:43 2016 +0900

    glamor: Avoid generating GEM flink names for BOs shared via DRI3 (v2)

    We can't create our own struct amdgpu_buffer representation in this case
    because destroying that would make the GEM handle inaccessible to glamor
    as well. So just get the handle directly via dma-buf.

    (ported from radeon commit 391900a670addec39515f924265bfa9f8bfa9ec0,
     extended to cache BO handles in the private for non-DRI3 pixmaps as
     well)

    v2: Swap whole pixmap privates instead of just BOs in
        amdgpu_dri2_exchange_buffers to avoid invalidating cached BO handles

    Reviewed-by: Alex Deucher <<a href="mailto:alexander.deucher@amd.com">alexander.deucher@amd.com</a>></pre>
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