<html>
    <head>
      <base href="https://bugs.freedesktop.org/" />
    </head>
    <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 --- - SNA/Gen4 xrandr mangles the screen"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=63636">63636</a>
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>chris@chris-wilson.co.uk
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>SNA/Gen4 xrandr mangles the screen
          </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>All
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>sergio.callegari@gmail.com
          </td>
        </tr>

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

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

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

        <tr>
          <th>Component</th>
          <td>Driver/intel
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>xorg
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Hi,

there is an issue that causes 100% reproducible screen mangling of the screen
on Gen4 hardware, using sna.

I see it on a machine with displayport. Attaching the exernal screen and
running

xrandr --output DP1 --auto --primary --output LVDS1 --off

is sufficient to mangle the whole screen. I do not know if this also happens
with VGA screens (i.e. without displayport), but I suspect it is the case.

Note that after having corrupted the screen with the command above, you succeed
in blindly writing

xrandr --output LVDS1 --auto --primary --output DP1 --off

then screen is restored.

Also note that you can make the problematic command work fine, if you split it
in two steps

xrandr --output DP1 --primary --auto --output LVDS1 --auto --right-of DP1
xrandr --output DP1 --auto --primary --output LVDS1 --off

Thanks for the attention!</pre>
        </div>
      </p>
      <hr>
      <span>You are receiving this mail because:</span>
      
      <ul>
          <li>You are the QA Contact for the bug.</li>
      </ul>
    </body>
</html>