I have a similar issue on my Hewlett-Packard HP Z820 Workstation after upgrading from 15.10 to 16.04. I have attached the associated kernel bug log. I have the latest BIOS flashed.
When this happens the system is completely unresponsive (neither Ctrl+Alt+Backspace nor Ctrl+Alt+F1 do anything). However, Alt+SysRec while typing REISUB does reboot the sytem. The out of kernel module is VirtualBox. If I manage to reproduce this without vboxdrv loaded I will fine a new bug. ** Attachment added: "bug.txt" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1575467/+attachment/4657443/+files/bug.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1575467 Title: [Dell Inspiron 3451] WARNING: CPU: 1 PID: 1297 at /build/linux-lts- utopic-vy2yyy/linux-lts- utopic-3.16.0/drivers/gpu/drm/i915/intel_display.c:1743 vlv_wait_port_ready+0x126/0x170 [i915]() To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1575467/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
