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      <base href="https://bugs.freedesktop.org/" />
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Priority</th>
          <td>medium
          </td>
        </tr>

        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW --- - i855gm: Display corruption in presence of graphics memory pressure"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=79843">79843</a>
          </td>
        </tr>

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

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

        <tr>
          <th>Summary</th>
          <td>i855gm: Display corruption in presence of graphics memory pressure
          </td>
        </tr>

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

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Linux (All)
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>bonbons67@internet.lu
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>x86 (IA32)
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>XOrg CVS
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>DRM/Intel
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>DRI
          </td>
        </tr></table>
      <p>
        <div>
        <pre>As determined with the help if Chris, on my i855GM system graphics corruption
seems to be triggered by i915 moving objects to/from GPU memory/aperture.

The corruption is visible either as:
- ghost-screenshot of some previously displayed surface, usually reflowed to
different width
- on some GTK applications, on scroll down by 1 line all the rest of the
surface gets repainted with repetitions of new line (common on hexchat/xchat,
but also mail view pane of claws-mail or pidgin message window). Scroll-up is
not affected.


History of theses corruptions: exist since a long time, show up mostly when
compositing (in Enlightenment, maybe due to fallback to software rendering as E
wants shaders for OpenGL acceleration)

Latest software stack used for testing:
- Kernel "drm-intel-nightly: 2014y-06m-02d-19h-49m-25s" on top of 3.15-rc8
- x11-libs/libdrm-2.4.52
- xf86-video-intel GIT from 31 may 2014

See also mail exchange with Chris:
  Message-ID: <<a href="mailto:20140427223402.572010a9@neptune.home">20140427223402.572010a9@neptune.home</a>>
which ended with:
  "Hmm. They do suggest that your system is under memory pressure - it has
to move objects in and out the GPU address space regularly - but they
don't suggest that you are out of memory."</pre>
        </div>
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