<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [CI][BAT] igt@kms_chamelium@(hdmi|dp)-hpd-fast|igt@kms_chamelium@dp-edid-change-during-suspend - fail - Failed assertion: igt_hotplug_detected(mon, HOTPLUG_TIMEOUT)" href="https://bugs.freedesktop.org/show_bug.cgi?id=111045#c36">Comment # 36</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [CI][BAT] igt@kms_chamelium@(hdmi|dp)-hpd-fast|igt@kms_chamelium@dp-edid-change-during-suspend - fail - Failed assertion: igt_hotplug_detected(mon, HOTPLUG_TIMEOUT)" href="https://bugs.freedesktop.org/show_bug.cgi?id=111045">bug 111045</a> from <a class="email" href="mailto:imre.deak@intel.com" title="Imre Deak <imre.deak@intel.com>"> Imre Deak</a> <pre>(In reply to emersion from <a href="show_bug.cgi?id=111045#c34">comment #34</a>) > (In reply to Imre Deak from <a href="show_bug.cgi?id=111045#c15">comment #15</a>) > > If unplugging a DP-alt display while there is an active modeset on it, and > > then replugging the DP-alt display, the HW/FW/driver won't signal the > > corresponding plug-in hotplug event until the mode is disabled. > > What happens if legacy userspace doesn't react to hotplug events? We need to > re-enable the output automatically on hotplug. As of now, legacy userspace > won't work on DP-alt. > > I'm leaning towards marking this as a kernel bug. If userspace doesn't > disable the mode, the kernel should re-enable it on hotplug. The same is true for anything connected in DP-MST mode too though: you connect an MST display, disconnect, then reconnect it, then the mode won't be re-enabled automatically on the display, unless user space processes the hotplug events. So the requirement for user space to do proper hotplug event processing is not specific to USB-C connectors. Why do you think we should handle USB-C connectors specially (and have the user space hotplug processing requirement only for DP-MST connectors)? We would need a very good justification listing the actual legacy userspace instances you mentioned (since there hasn't been any actual complaints for these even for MST).</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> </ul> </body> </html>