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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 --- - [bisected] kernel 3.7.0-rc1 breaks 6950 (CAYMAN)"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=56139">56139</a>
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>dri-devel@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>[bisected] kernel 3.7.0-rc1 breaks 6950 (CAYMAN)
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>major
          </td>
        </tr>

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

        <tr>
          <th>OS</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>alexandre.f.demers@gmail.com
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>All
          </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/Radeon
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>DRI
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Using ArchLinux 64, own built kernel (vanilla) with an HD 6950 (CAYMAN).

When testing kernel 3.7-rc1, the screen becomes unreadable. It's either
completely black or in a flickering state making the display unusable. It is
very similar to what was observed in <a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED DUPLICATE - Latest radeon dri driver on HD6950 with GRUB set gfxpayload=$linux_gfx_mode put the display in a flickering state"
   href="show_bug.cgi?id=43655">bug 43655</a>.

At the time of <a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED DUPLICATE - Latest radeon dri driver on HD6950 with GRUB set gfxpayload=$linux_gfx_mode put the display in a flickering state"
   href="show_bug.cgi?id=43655">bug 43655</a>, the problem had been fixed by
<a href="http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=81ee8fb6b52ec69eeed37fe7943446af1dccecc5">http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=81ee8fb6b52ec69eeed37fe7943446af1dccecc5</a>.
So it was working OK with kernel 3.6.

I've bisected between kernel 3.6 and 3.7-rc1 and the faulty identified commit
is the following:
62444b7462a2b98bc78d68736c03a7c4e66ba7e2 is the first bad commit
commit 62444b7462a2b98bc78d68736c03a7c4e66ba7e2
Author: Alex Deucher <<a href="mailto:alexander.deucher@amd.com">alexander.deucher@amd.com</a>>
Date:   Wed Aug 15 17:18:42 2012 -0400

    drm/radeon: properly handle mc_stop/mc_resume on evergreen+ (v2)

    - Stop the displays from accessing the FB
    - Block CPU access
    - Turn off MC client access

    This should fix issues some users have seen, especially
    with UEFI, when changing the MC FB location that result
    in hangs or display corruption.

    v2: fix crtc enabled check noticed by Luca Tettamanti

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

:040000 040000 3e0d33c9b4eda29ced814fe9a863efe63e53f14c
4932561607b160734ec1eade927a9fe18c9f3f1b M    drivers</pre>
        </div>
      </p>
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