<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - dc=1 kernels somehow trigger a disconnect of an lg ultrawide monitor during DP link training while attempting a wakeup" href="https://bugs.freedesktop.org/show_bug.cgi?id=106529#c2">Comment # 2</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - dc=1 kernels somehow trigger a disconnect of an lg ultrawide monitor during DP link training while attempting a wakeup" href="https://bugs.freedesktop.org/show_bug.cgi?id=106529">bug 106529</a> from <a class="email" href="mailto:michel@daenzer.net" title="Michel Dänzer <michel@daenzer.net>"> Michel Dänzer</a> <pre>(In reply to Mariusz Mazur from <a href="show_bug.cgi?id=106529#c1">comment #1</a>) > Pre-DC codepaths did not have an issue like this at all until Michel Dänzer > created this patch: <a href="https://patchwork.freedesktop.org/patch/209464/">https://patchwork.freedesktop.org/patch/209464/</a> for bug > 105308 thereby introducing a problem with the same effects (DC monitor gets > disconnected on wakeup, which on multi-display causes issues) via a quite > different approach (a deliberate DRM_MODE_DPMS_OFF & ON). But that should be > a separate bug, I think. FWIW, that change should have no direct effect on whether the display is considered connected or disconnected. The only change is that when the driver is notified that a DP display is "disconnected" (which can also happen without a physical disconnection, e.g. if the display is turned off), it doesn't immediately turn off the GPU's DP source anymore, but waits until either userspace asks to turn it off, or it gets notified that a display is "connected" again. Both "disconnect" / "connect" hotplug events are sent to userspace before and after this change. I suspect that immediately turning off the DP source simply happened to delay sending the "disconnect" hotplug event to userspace enough to avoid the issue on your system.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>