Disabling the graphics card seems to trigger an ACPI hotplug event which seems to remove the device from the system.
Could you prevent bbswitch from loading at boot (nvidia/nouveau should not load either), then report the output of the following steps including a dmesg log: sudo modprobe bbswitch load_state=-1 lspci -nnvvd10de: sudo tee /proc/acpi/bbswitch <<<OFF lspci -nnvvd10de: sudo tee /proc/acpi/bbswitch <<<ON lspci -nnvv10de: ** Changed in: bbswitch (Ubuntu) Status: New => Incomplete ** Changed in: bbswitch (Ubuntu) Assignee: (unassigned) => Peter Wu (lekensteyn) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1318040 Title: bbswitch prevents suspend and taints kernel To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/bbswitch/+bug/1318040/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs