<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - Regression with Dell TB16 dock and Linux kernel 4.16.x" href="https://bugs.freedesktop.org/show_bug.cgi?id=106250#c25">Comment # 25</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - Regression with Dell TB16 dock and Linux kernel 4.16.x" href="https://bugs.freedesktop.org/show_bug.cgi?id=106250">bug 106250</a> from <a class="email" href="mailto:stanislav.lisovskiy@intel.com" title="Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>"> Stanislav Lisovskiy</a> <pre>I think I've identified the real reason for this bug: the problem is that kernel allocates dynamically new connector id for DP MST devices each time it is plugged/unplugged and adding/removing correspondent connectors. That seems to confuse userspace into thinking that connector is still in a connected state, thus leading to a lost modeset. In order to fix that, we must either return only active DP MST connectors or check connector states more carefully on userspace side. I've implemented both fixes, however not sure which one is correct and some things still need to be understood. However, it could be helpful if somebody tries those and report if it fixes problem. Userspace is implemented for Intel DDX, something similar I guess might be needed for XWayland or modesetting.</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>