I did a fresh install of cinnamon 17.0.2 and system update immediately afterwards yesterday and noticed that there is no lock screen after I close the lid (the laptop suspends) and re-open it. It gets directly back to session without asking for password.
Manual launching of the screensaver (by clicking on lock screen button at start menu, or by pressing Ctrl+Alt+L) works alright.
Auto-launching of the screensaver (by leaving inactive for some time) works OK.
I think I got it now: cinnamon-screensaver-pam-helper is actually placed in the wrong path. It's not supposed to end up in subdir /usr/lib/cinnamon-screensaver/cinnamon-screensaver-pam-helper but in /usr/lib directly
I made a soft link from
/usr/lib/cinnamon-screensaver-pam-helper and rebooted, that didn't solve the problem though.
And in this post (Lock screen not working on Manjaro Cinnamon) the solution is to install
python--setproctitle, which appears to be pre-installed with the distro already.
Machine: Dell inspiron 15-7560
OS: Manjaro cinnamon 17.0.2
GPU: GeForce 940MX
Graphics driver: video-hybrid-intel-nvidia-bumblebee
cinnamon-screensaver version: 3.4.1-2 community