Finally this is not a duplicate of #982889, although it belongs to the same class of race condition in X bugs. So I removed duplicate info.
** This bug is no longer a duplicate of bug 982889 X trying to start before plymouth has finished using the drm driver -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-intel in Ubuntu. https://bugs.launchpad.net/bugs/1129220 Title: Fails to boot to X, but starting lightdm afterward works To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/1129220/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp