<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - Unable to detect monitor modes connected to a TB16 Dell dock" href="https://bugs.freedesktop.org/show_bug.cgi?id=111507#c7">Comment # 7</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - Unable to detect monitor modes connected to a TB16 Dell dock" href="https://bugs.freedesktop.org/show_bug.cgi?id=111507">bug 111507</a> from <a class="email" href="mailto:stanislav.lisovskiy@intel.com" title="Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>"> Stanislav Lisovskiy</a> <pre>I've looked briefly into the log. There seems to be multiple DP MST connectors detected and some modes were pruned as invalid. Another thing is that if correspondent i915_display_info debugfs entry doesn't display anything except this: connector 118: type DP-5, status: connected physical dimensions: 600x340mm subpixel order: Unknown CEA rev: 3 it means that it could not find an intel_encoder, which in turn means that encoder->pre_enable function was not called, which was supposed to assign encoder to correspondent connector. This is possible if intel_encoders_pre_enable function skips that encoder, which can happen if connector state crtc doesn't match the base crtc. So indeed that could be related to the patch you have bisected to or some other problem which makes this possible. To check my hypothesis, I have a small patch, which will output a specific message if it skips encoder->pre_enable call, so that we know then for sure. Please apply this patch, rebuild kernel and try again, with drm.debug enabled.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>