<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [SKL-U] System hang when plug in a VGA monitor" href="https://bugs.freedesktop.org/show_bug.cgi?id=91791#c7">Comment # 7</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [SKL-U] System hang when plug in a VGA monitor" href="https://bugs.freedesktop.org/show_bug.cgi?id=91791">bug 91791</a> from <a class="email" href="mailto:gary.c.wang@intel.com" title="Gary Wang <gary.c.wang@intel.com>"> Gary Wang</a> <pre>Created <a href="attachment.cgi?id=119128" name="attach_119128" title="System hung when plug-in DP MST-enabled hub in Intel SKL-U CRB">attachment 119128</a> <a href="attachment.cgi?id=119128&action=edit" title="System hung when plug-in DP MST-enabled hub in Intel SKL-U CRB">[details]</a> System hung when plug-in DP MST-enabled hub in Intel SKL-U CRB I use DP 1.2 MST-supported HUB (Sunix IT DisplayPort to Dual Graphics Splitter) to test this issue in SKU-U Intel CRB, two DPs input, one miniDP output. This DP MST hub works well in my win7 Lenovo X230NB via miniDP port. But it also suffer from system hung in Ubuntu 15.04 with drm-intel-nightly-2015/10/19 when plug-in DP MST Hub to CRB's miniDP port. ... Feb 11 16:16:03 test kernel: [ 96.395534] [drm:intel_dp_set_signal_levels] Using pre-emphasis level 0 Feb 11 16:16:03 test kernel: [ 96.412066] [drm:intel_dp_set_signal_levels] Using signal levels 00000000 Feb 11 16:16:03 test kernel: [ 96.412068] [drm:intel_dp_set_signal_levels] Using vswing level 0 Feb 11 16:16:03 test kernel: [ 96.412069] [drm:intel_dp_set_signal_levels] Using pre-emphasis level 0 Feb 11 16:16:03 test kernel: [ 96.428626] [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too ma Feb 11 16:16:03 test kernel: [ 96.428847] [drm:intel_dp_link_training_channel_equalization [i915]] *ERROR* ....</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are on the CC list for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>