<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 - KHR-GL43.compute_shader.resource-texture fails with MCS fast clears disabled"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=109113">109113</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>KHR-GL43.compute_shader.resource-texture fails with MCS fast clears disabled
          </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>kenneth@whitecape.org
          </td>
        </tr>

        <tr>
          <th>QA Contact</th>
          <td>intel-3d-bugs@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>ghugesss@gmail.com, jason@jlekstrand.net, nanleychery@gmail.com, topi.pohjolainen@intel.com
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=142859" name="attach_142859" title="Patch to narrow the CTS test to a smaller reproducer">attachment 142859</a> <a href="attachment.cgi?id=142859&action=edit" title="Patch to narrow the CTS test to a smaller reproducer">[details]</a></span> <a href='page.cgi?id=splinter.html&bug=109113&attachment=142859'>[review]</a>
Patch to narrow the CTS test to a smaller reproducer

I believe I've found a bug with MCS and slow clears.

If I disable fast clears (hack brw_blorp.c to add "can_fast_clear = false"),
then KHR-GL43.compute_shader.resource-texture fails on my Kabylake system.  The
test clears a 4x MSAA 4x16 R32G32B32A32_FLOAT texture, which is using the CMS
layout.  Disabling CMS/MCS also fixes it.  (There are actually two, one is a
single slice, the other is a 2-slice array texture.  Both are broken.)  It then
samples the textures with a compute shader.

Fast clears ought to be optional - I think they may be masking a bug.

The attached patch to the CTS test narrows it down to a much smaller test case.

This is fairly outside of my expertise, so I'd appreciate it if some MCS
experts could take a look (without ruining your holiday plans)...thanks!</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>