I'm running Ubuntu 16.04 with multiple desktops, on three different architectures, first is an Intel Desktop, the other is an AMD Desktop and the third on Intel MacMini multi-boot system. I mostly use GNOME Clasic Flashback, and Ubuntu MATE Desktop environments, beside Unity, as well as, the Xfce.
Recently I discovered that both, Ubuntu-MATE and Xfce, fail to suspend either of above mentioned computers when they stay idle over the limit set in their respective Power Management windows. However, manually suspending them either from Power Down Window, by pressing the Suspend button, or by running either systemctl suspend or systemctl hibernate from a terminal works as expected. All the computers go to sleep or they turn off in case I run systemctl hibernate, and they all promptly return back to their last running state Ubuntu MATE, as well as Xfce, were in before it got suspended or put into hibernate state.
This inconsistent behaviour is only occurring in Ubuntu MATE Desktop GUI and in Xfce. Neither GNOME Clasic Flashback, nor Unity experience the same inconsistencies. They all go to sleep when they are idle for the specified permitted Idle time, and have no trouble resuming to their last running state upon waking up.
The fact, that suspend works from the command line regardless which display manager I use, and that automatic suspension fails only in Ubuntu MATE and Xfce, points out that there is something very simple misconfigured in those two (MATE's, and Xfce's) Power Management GUIs.
Can anybody, please, give me some pointers where to turn to find a solution to this problem.
Thank you, in advance
Bookmarks