gdm multiple users wayland systemd TTY hickup
I am using gdm to login. When multiple users are active (i.e. the first user locks the screen and the other logs in), the first login attempt for the second user seems to work fine at first glance, but within at maximum 10 seconds gnome stops and the gdm screen is shown again. This behavior is not observed for a second login of the second user.
To debug, I did the following:
- Login as first user
- Show sessions with
loginctl
: One session is active: session 2 (tty2, seat0, first user) - Lock screen
- Login as second user (immediately returns to login screen/gdm)
- Login as first user
- Show sessions with
loginctl
: Three sessions are active: session 2 (tty2, seat0, first user), session 5 (seat0, tty4, second user), session c3 (tty1, gdm)
I therefore assume that for some reasons, the ttys are mixed up (The second user logs in successfully, but the wrong screen is shown)
This behavior is observed only on wayland, i.e. setting WaylandEnable=false
under [daemon]
in /etc/gdm/custom.conf
solves the issue.
One difference I have observed for X11 is that after the first login of the first user, there are already two sessions: session 2 (first user, seat0, tty2) and session c1 (gdm, seat0, tty1). After login of the second user, he gets session 4 (seat0, tty3).
My system is a Intel® Core™ i7-7500U CPU @ 2.70GHz × 4 with Mesa Intel® HD Graphics 620 (KBL GT2). Gnome version is 3.36.2