Bug 116541

Summary:	Switching consoles using Ctl-Alt-Fn keys produces a Black screen only.
Product:	Other	Reporter:	Saptech (saptech)
Component:	Other	Assignee:	other_other
Status:	NEW ---
Severity:	high
Priority:	P1
Hardware:	x86-64
OS:	Linux
Kernel Version:	kernel 4.4.x	Subsystem:
Regression:	No	Bisected commit-id:

Description Saptech 2016-04-16 16:07:10 UTC

I noticed this behavior when using the Switch-User(dm-tool) feature running Mate DE & LightDM and running kernel 4.4. Running kernel 4.3 does not display this behavior. 

With two or more user accounts created, user1 sign in. If user2 need to login and user1 Switch User, it will bring up the the display manager. User2 can sign in but when user2 Switch User, it returns to a Blank screen. The only way to get out of it is to reboot the system using the power button. This behavior happen using the Ctl-Alt-Fn keys also.

I've noticed this happen with Debian Testing, Archlinux and a few other distros that are running kernel 4.4.

Steps to Reproduce: Create two users, switch consoles between the two users while running kernel 4.4 or higher, it should produce a black screen and only option is to reboot the computer.