<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - Kernel "NULL pointer dereference" with MST monitor on HSW" href="https://bugs.freedesktop.org/show_bug.cgi?id=97666#c14">Comment # 14</a> on <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - Kernel "NULL pointer dereference" with MST monitor on HSW" href="https://bugs.freedesktop.org/show_bug.cgi?id=97666">bug 97666</a> from <a class="email" href="mailto:carlos.santa@intel.com" title="Carlos Santa <carlos.santa@intel.com>"> Carlos Santa</a> <pre>Finally, I am able to consistently repro this problem on HWS/BDW by disabling RC6 power states (i915.enable_rc6=0) at least since the drm-nightly from Oct 1 (<a href="http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-nightly/2016-10-01/">http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-nightly/2016-10-01/</a> The tip of the drm-nightly at least since Oct 7 doesn't repro the null pointer exception. The display stays black but forcing a mode setting change switching from text mode (CTRL+ ALT + F1) to gfx mode (C+A+F7) "fixes" the black screen and the UI screen is able to come back. Next steps: 1. Ask Tomi or someone else to see if they no longer are able to repro the null pointer on the latest drm-nightly. 1. Continue bisecting the tree to see when the null pointer disappear as it seems in the latest nightly I am not able to see the nullpointer anymore.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are on the CC list for the bug.</li> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>