lightdm + lightdm-gtk-greeter It is OK if I start computer normally. But when I locked screen with 'dm-tool lock',and light the screen again.My screen just flashes. I can see the login panel moves very fast from right to left on my screen. I can input my passwd, and login my system, but the screen just blacked after I succfully logined in. I had to use 'xrandr --output eDP1 --off && xrandr --output --auto' to light my screen again. here is an image when the screen flashes: -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.freedesktop.org/archives/lightdm/attachments/20150719/0140ceba/attachment-0001.html> -------------- next part -------------- A non-text attachment was scrubbed... Name: 612022797.jpg Type: image/jpeg Size: 89415 bytes Desc: not available URL: <http://lists.freedesktop.org/archives/lightdm/attachments/20150719/0140ceba/attachment-0001.jpg>