YS1, unfortunately you didn't follow all the instructions in https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1577162/comments/2 and what it provided is useless.
** Attachment removed: "Dependencies.txt" https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1577162/+attachment/4698337/+files/Dependencies.txt ** Attachment removed: "JournalErrors.txt" https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1577162/+attachment/4698338/+files/JournalErrors.txt ** Attachment removed: "ProcEnviron.txt" https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1577162/+attachment/4698339/+files/ProcEnviron.txt ** Description changed: When I boot my laptop and get to the lightdm login prompt, the screen blacks out for a fraction of second. This happens each time, only once, and does not prevent logging in. In fact it is not only a display glitch : if I start to type my password before the blackout, the typed characters are lost when normal display resumes. So lightdm might be restarting. This is only mildly annoying, but I am also experiencing other graphical problems which may be or not be related (namely #1568604). ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: lightdm 1.18.1-0ubuntu1 ProcVersionSignature: Ubuntu 4.4.0-22.38-generic 4.4.8 Uname: Linux 4.4.0-22-generic x86_64 NonfreeKernelModules: wl ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 CurrentDesktop: XFCE Date: Sun May 1 14:55:29 2016 InstallationDate: Installed on 2016-04-22 (8 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1) SourcePackage: lightdm UpgradeStatus: No upgrade log present (probably fresh install) - --- - ApportVersion: 2.20.1-0ubuntu2.1 - Architecture: amd64 - CurrentDesktop: XFCE - DistroRelease: Ubuntu 16.04 - InstallationDate: Installed on 2016-04-22 (78 days ago) - InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1) - NonfreeKernelModules: wl - Package: xorg 1:7.7+13ubuntu3 - PackageArchitecture: amd64 - ProcVersionSignature: Ubuntu 4.4.0-30.49-generic 4.4.13 - Tags: third-party-packages xenial - Uname: Linux 4.4.0-30-generic x86_64 - UpgradeStatus: No upgrade log present (probably fresh install) - UserGroups: adm bumblebee cdrom dip lpadmin plugdev sambashare sudo - _MarkForUpload: True -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1577162 Title: Screens briefly blacks out at lightdm prompt Status in xorg package in Ubuntu: Incomplete Bug description: When I boot my laptop and get to the lightdm login prompt, the screen blacks out for a fraction of second. This happens each time, only once, and does not prevent logging in. In fact it is not only a display glitch : if I start to type my password before the blackout, the typed characters are lost when normal display resumes. So lightdm might be restarting. This is only mildly annoying, but I am also experiencing other graphical problems which may be or not be related (namely #1568604). ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: lightdm 1.18.1-0ubuntu1 ProcVersionSignature: Ubuntu 4.4.0-22.38-generic 4.4.8 Uname: Linux 4.4.0-22-generic x86_64 NonfreeKernelModules: wl ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 CurrentDesktop: XFCE Date: Sun May 1 14:55:29 2016 InstallationDate: Installed on 2016-04-22 (8 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1) SourcePackage: lightdm UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1577162/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp