<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 --- - backlight switches of when starting X since kernel-3.13"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=75917">75917</a>
          </td>
        </tr>

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

        <tr>
          <th>Summary</th>
          <td>backlight switches of when starting X since kernel-3.13
          </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>nl@gnuffy.net
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>Other
          </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>After updating from linux 3.12.8 to 3.13 my display backlight 
switches off when starting X. 
The kernel doesn't  crash, it just switched off the backlight.

Hardware name: Acer Aspire 3820T/JM31_CP, BIOS V1.19 10/27/2010

This is a notebook with an intel/radeon hybrid graphics. 
I use  intel for my X. I report this as radeon problem because 
git bisect (on linux-stable tree) showed the following commit 
as the cause of my problem:

10ebc0bc09344ab6310309169efc73dfe6c23d72 is the first bad commit
commit 10ebc0bc09344ab6310309169efc73dfe6c23d72
Author: Dave Airlie <airlied at redhat.com>
Date:   Mon Sep 17 14:40:31 2012 +1000

    drm/radeon: add runtime PM support (v2)

    This hooks radeon up to the runtime PM system to enable
    dynamic power management for secondary GPUs in switchable
    and powerxpress laptops.

    v2: agd5f: clean up, add module parameter

    Signed-off-by: Dave Airlie <airlied at redhat.com>
    Signed-off-by: Alex Deucher <alexander.deucher at amd.com>


Please let me know if you need addititonal information.</pre>
        </div>
      </p>
      <hr>
      <span>You are receiving this mail because:</span>
      
      <ul>
          <li>You are the assignee for the bug.</li>
      </ul>
    </body>
</html>