Comment # 2 on bug 1054214 from Dr. Werner Fink

(In reply to Imobach Gonzalez Sosa from comment #1)
> As it is related to login service, I would ask systemd maintainers. Please,
> could you have a look?
> 
> Thanks!

Hmmm ... if it works on SLE but not on Leap it is unlikly that systemd is the
problem. Systemd generates the appropiate standard agetty services from  the
kernels informations below /sys/class/tty/console/active AND
/sys/class/tty/tty0/active (if required on the kernels command line).

(In reply to Takashi Iwai from comment #0)
> Created attachment 737009 [details]
> screenshot of serial console output
> 
> After a fresh installation of Leap 42.3 with the full updates on KVM, reboot
> with console=ttyS0 boot option.  On serial console, you can login.
> 
> But at the first login, it echoes the typed user name ("root" in the
> screenshot below).  Then after giving the password and RETURN, nothing
> happens.
> 
> After 60 seconds, it times out, and the login prompt appears again.
> Now you can login normally.
> 
> The symptom seems appearing only on openSUSE, not on SLE.  It's reproducible.

Ever tried the option

   console=ttyS0 console=tty0

to get both a serial and virtual line(s) ?