[REGRESSION BISECTED] 6.8-rc1 - Wayland hangs when connecting via VNC or RDP

From: Paul Zimmerman
Date: Wed Jan 24 2024 - 14:48:12 EST


When I attempt to connect via VNC or RDP to my Ubuntu desktop, the Wayland
server seems to hang. The desktop GUI no longer works either locally or
remotely. I can still log in via ssh, so the system is still alive,
but the GUI is
frozen. If I boot into Xorg instead, everything works fine. Kernel 6.7
works fine
also.

I bisected this to commit f7fe64ad0f22 "drm/sched: Split free_job into
own work item".
That commit does not revert cleanly however.

I don't see anything in dmesg when this happens. Here is a snippet from
journalctl when it happens:
Jan 23 16:14:30 paulz-Precision-5820-Tower systemd[2826]: Started
Tracker metadata extractor.
Jan 23 16:14:55 paulz-Precision-5820-Tower systemd[2826]: Started
Application launched by gnome-session-binary.
Jan 23 16:16:47 paulz-Precision-5820-Tower
gnome-remote-desktop-daemon[4158]: [16:16:47:810] [4158:4896]
[ERROR][com.freerdp.core.peer] - Incorrect RDP header.
Jan 23 16:16:47 paulz-Precision-5820-Tower
gnome-remote-desktop-daemon[4158]: [16:16:47:810] [4158:4896]
[ERROR][com.freerdp.core.peer] - peer_recv_callback:
CONNECTION_STATE_ACTIVE - peer_recv_pdu() fail
Jan 23 16:16:47 paulz-Precision-5820-Tower
gnome-remote-desktop-daemon[4158]: [16:16:47:810] [4158:4896]
[ERROR][com.freerdp.core.transport] - transport_check_fds:
transport->ReceiveCallback() - -1
Jan 23 16:16:47 paulz-Precision-5820-Tower gnome-remote-de[4158]:
Unable to check file descriptor, closing connection
Jan 23 16:16:47 paulz-Precision-5820-Tower systemd[1]:
run-user-1001-gnome\x2dremote\x2ddesktop-cliprdr\x2d9Tp4LD.mount:
Deactivated successfully.

This is on an x86_64 Xeon system running Ubuntu 22.04.3. Any hints on how to
debug this further? Is there a way to turn on additional debug prints for this?

Thanks,
Paul