@perryhelionsemail - I am really hesitant to removing the max_cstate boot flag: I had to set this in order to avoid random and total system freezes. And that bug seems to be anything but fixed: https://bugzilla.kernel.org/show_bug.cgi?id=109051
So, with due respect to curiosity – not gonna try that. ;) However, it seems I found a solution for now for my flickering graphics issues. I tried Gnome Shell (Ubuntu's default DE). There I did NOT encounter any flickering. But Gnome Shell isn't a Desktop Environment I would want to settle on – I'll save you my random rant about it. :) And that was not my solution. In trying to find a fix for my previously mentioned Cinnamon login-crash bug, I had upgraded Cinnamon to the latest stable version 3.8.3 via a PPA (the current version in Ubuntu's repo is 3.6.7). Today, I purged the PPA and downgraded Cinnamon to the older Ubuntu's repo version. As a result, the flickering issues with the patched kernel seem to be gone, so I'm mostly good for now, as far as I can see. :) To summarize: - The patched 4.15.0-24 kernel enables me to suspend-to-ram. - The patched 4.15.0-24 kernel brings a new issue for me: A minute-long wait before I get to the Ubuntu greeter and am able to login to a DE. This does not happen in 4.15.0-23. - The patched 4.15.0-24 in combination with latest Cinnamon 3.8.3 (via PPA) causes graphics flickering big time. This does not occur in 4.15.0-23, either. So, while indeed restoring suspend, the patch still seems to be missing something. @kaihengfeng - Is there any way I might help debugging or provide additional info? ** Bug watch added: Linux Kernel Bug Tracker #109051 https://bugzilla.kernel.org/show_bug.cgi?id=109051 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1774950 Title: Suspend fails in Ubuntu and Kubuntu 18.04 but works fine in Ubuntu and Kubuntu 17.10 (and on Kubuntu 18.04 using kernel 4.14.47) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1774950/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs