This bug is missing log files that will aid in diagnosing the problem. >From a terminal window please run:
apport-collect 1516216 and then change the status of the bug to 'Confirmed'. If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'. This change has been made by an automated script, maintained by the Ubuntu Kernel Team. ** Changed in: linux (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1516216 Title: X fails to start, starting with kernel version 3.13.0-66 including 3.13.0-68 Status in linux package in Ubuntu: Incomplete Bug description: System: Ubuntu 14.04 Graphics Card: Geforce GTX 670 Graphics Driver: nvidia-352.55 Starting with kernel 3.13.0-66, the start of X / default display manager results in a black screen. My observations are: - When I get this black screen, I cannot CTRL+ALT+F1 into a text console - Pressing the power button in this state leads to a proper shutdown (which I guess means that it is not a complete kernel panic). - When using these latest kernel, the graphics behavior during boot-up also has changed. Instead of a graphical animation, the system boots in text mode (I can see the syslog output), and at the moment I should get the display manager, the screen goes black. My work-around so far has been to boot kernel 3.13.0-65 instead of 3.13.0-66, 3.13.0-67, or 3.13.0-68. So far this has worked reliably. However today, booting kernel 3.13.0-65 has resulted in a black screen as well. Fortunately, I found a new work-around: I can boot kernel 3.13.0-68 in recovery mode, and chose simply "continue" in the recovery console. With this modification of the boot process, X will start. In the syslog, I can see some suspicious messages, around the time X should start: "BUG: unable to handle kernel NULL pointer dereference at (null)". I have attached a syslog contain some failed starts as well as a successful one. Another suspicion is that the problem is related having an Oculus Rift DK2 connected. In particular, this requires to use a custom Xorg.conf which runs individual X screens for the main display and the Oculus Rift. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1516216/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp