请您告诉我如何在系统空闲且 lightdm 登录屏幕处于活动状态（没有用户登录）时禁止在 20 或 30 分钟内进入挂起模式。
在我们的机器上，诊断命令提供以下 dconf 参数：
# sudo -H -u lightdm dbus-launch --exit-with-session gsettings list-recursively org.gnome.settings-daemon.plugins.power
org.gnome.settings-daemon.plugins.power lid-close-ac-action 'suspend'
org.gnome.settings-daemon.plugins.power time-critical 300
org.gnome.settings-daemon.plugins.power power-button-action 'suspend'
org.gnome.settings-daemon.plugins.power lid-close-suspend-with-external-monitor false
org.gnome.settings-daemon.plugins.power button-hibernate 'hibernate'
org.gnome.settings-daemon.plugins.power idle-dim true
org.gnome.settings-daemon.plugins.power button-power 'suspend'
org.gnome.settings-daemon.plugins.power lid-close-battery-action 'suspend'
org.gnome.settings-daemon.plugins.power priority 0
org.gnome.settings-daemon.plugins.power idle-brightness 30
org.gnome.settings-daemon.plugins.power active false
org.gnome.settings-daemon.plugins.power critical-battery-action 'hibernate'
org.gnome.settings-daemon.plugins.power button-suspend 'suspend'
org.gnome.settings-daemon.plugins.power button-sleep 'hibernate'
org.gnome.settings-daemon.plugins.power percentage-critical 3
org.gnome.settings-daemon.plugins.power sleep-inactive-ac-timeout 0
org.gnome.settings-daemon.plugins.power sleep-inactive-ac-type 'nothing'
org.gnome.settings-daemon.plugins.power ambient-enabled true
org.gnome.settings-daemon.plugins.power notify-perhaps-recall true
org.gnome.settings-daemon.plugins.power percentage-low 10 …