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    <head>
      <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 - [BSW] image corruption issue after edd849e5448c4f6ddc04a5fa1ac5479176660c27"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=102818">102818</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>[BSW] image corruption issue after edd849e5448c4f6ddc04a5fa1ac5479176660c27
          </td>
        </tr>

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

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

        <tr>
          <th>Hardware</th>
          <td>x86-64 (AMD64)
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Linux (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>freedesktop@nmacleod.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>A user has reported an intermittent issue since 4.12-rc1 which manifests as a
"z" shaped flicker/breakup of the displayed image.

The OS is LibreELEC with latest mainline kernel, running Kodi 18.

Since a picture is worth a thousand words, you can view the issue in two short
videos:

Video #1[1]: flicker at 1s, 10s and 12s
Video #2[2]: flicker at 1s and 8s

The user has tested with two different HDMI cables and two different TVs, and
the result is the same.

I bisected the kernel with the user (bisect log attached) and the bad commit[3]
is:

Merge tag 'drm-misc-next-2017-03-21' of
git://anongit.freedesktop.org/git/drm-misc into drm-next

Unfortunately this is a merge commit, but it seems to be in the right area.

The kernel log with "drm.debug=0xe" is attached, as is Xorg.0.log.

Unfotunately it hasn't been possible to obtain a vbios dump.

The user has tried on two TVs with two different cables, and the same problem
is present with all combinations:

TV #1: Sony KDL 32EX521 SW:PKG3-309-EUA-0104 (1080p, 6 years old)
TV #2: Sony KDL 49X8305C SW:PKG3-473-0107EUB (4K, 1 year old)
Cable #1: Belkin High speed 3m #49749
Cable #2: Startech 1m Highspeed 20276

The PC configuration is:

CPU: Intel Atom x5-E8000 (Braswell) @ 1.04GHz (SolidRun IB8000 SOM[4])
GPU: Intel HD Graphics 400
Driver: intel-vaapi-driver 1.8.3, libva 1.8.3, mesa 17.2

The issue is still present with kernel 4.13.2 and 4.14-rc1.

I'd be happy to create test builds with patches for the user to try out.

Many thanks.

1. <a href="http://milhouse.libreelec.tv/other/vsync_issue/IMG_0403.MOV">http://milhouse.libreelec.tv/other/vsync_issue/IMG_0403.MOV</a> (27MB)
2. <a href="http://milhouse.libreelec.tv/other/vsync_issue/IMG_0406.MOV">http://milhouse.libreelec.tv/other/vsync_issue/IMG_0406.MOV</a> (18MB)
3.
<a href="https://github.com/torvalds/linux/commit/edd849e5448c4f6ddc04a5fa1ac5479176660c27">https://github.com/torvalds/linux/commit/edd849e5448c4f6ddc04a5fa1ac5479176660c27</a>
4.
<a href="https://www.solid-run.com/intel-braswell-family/braswell-som-system-on-module/braswell-som-specifications/">https://www.solid-run.com/intel-braswell-family/braswell-som-system-on-module/braswell-som-specifications/</a></pre>
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      </p>


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