<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 - [CHV] Surface 3 does not get correct EDID from firmware"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=96255">96255</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>[CHV] Surface 3 does not get correct EDID from firmware
          </td>
        </tr>

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

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

        <tr>
          <th>Hardware</th>
          <td>All
          </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>stephenjust@gmail.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>On the Surface 3 (Atom x7 X8700), the kernel is unable to get the correct EDID
data for the display. As a result, the correct display dimensions are not set,
meaning that user-space programs that depend on this info do not have it. As an
example, Gnome would kick in to Hi-DPI mode if the correct dimensions were
available.

Windows seems to be able to fetch an EDID record for the display with the
proper dimensions set, and as far as I can tell it doesn't use any mechanisms
to override the EDID using a specific driver implying that the GPU could be
accessing it somehow.

I will attach an export of the Windows Registry showing what it can see. In
this file, DISPLAY\MEI9001\4 is the Surface's screen with the correct
dimensions specified.


Work around:
1. Build a kernel with CONFIG_DRM_LOAD_EDID_FIRMWARE=Y
2. Download attached EDID record (extracted on Windows), surface3.bin, to
/lib/firmware/edid/surface3.bin
3. Add drm_kms_helper.edid_firmware=DSI-1:edid/surface3.bin to your kernel line</pre>
        </div>
      </p>


      <hr>
      <span>You are receiving this mail because:</span>

      <ul>
          <li>You are on the CC list for the bug.</li>
          <li>You are the assignee for the bug.</li>
          <li>You are the QA Contact for the bug.</li>
      </ul>
    </body>
</html>