Comment 0 for bug 1757375

On 16.04 (XFCE session and others) and possibly later the power-manager is unable to suspend the system when the user is inactive. A PK user-agent dialog is presented for the user to authenticate first - and as this action occurs specifically when the user is idle and away the PC can end up having an unplanned loss of power when the battery is exhausted.

/var/log/auth.log shows:

polkitd(authority=local): Operator of unix-session:c2 FAILED to authenticate to gain authorization for action org.freedesktop.login1.suspend for system-bus-name::1.47 [xfce4-power-manager --restart --sm-client-id 2992705d4-6fa2-4fba-966c-f7631ecd0b46] (owned by unix-user:tj)

The problem seems to be "com.ubuntu.desktop.pkla" is missing an entry to allow Suspend. Currently it only has an entry for hibernate.

Adding the following stanza solves the issue:

[Enable suspend by default in logind]
Identity=unix-user:*
Action=org.freedesktop.login1.suspend;org.freedesktop.login1.inhibit-handle-suspend-key;org.freedesktop.login1;org.freedesktop.login1.suspend-multiple-sessions;org.freedesktop.login1.suspend-ignore-inhibit
ResultActive=yes
ResultInactive=yes