Failed to run Bumblebee
I have the common issue. When I try to run something through optirun, I get the following:
[13395.278406] [ERROR]Cannot access secondary GPU - error: [XORG] (EE) intel(0): [drm] failed to set drm interface version: Permission denied .
[13395.278522] [ERROR]Aborting because fallback start is disabled.
Ubuntu GNOME 14.04
NVIDIA Corporation GeForce GT 520M
Nvidia 331 driver
I've tried to reinstall nvidia and bumblebee packages, to remove something related with nvidia within /usr/share/X11/xorg.conf.d, uncomment BusID in the xorg.conf.nvidia file with no luck.
Until i found this workaround
I was having this problem too. For me, it was loading the default system config directory, see /var/log/Xorg.8.log:
3193.759 Using config file: "/etc/bumblebee/xorg.conf.nvidia"
3193.759 Using config directory: "/etc/bumblebee/xorg.conf.d"
3193.759 Using system config directory "/usr/share/X11/xorg.conf.d"
xorg.conf.d contains 20-intel.conf which contains the intel card definition. But it seems the order of loading these devices was messed up and xorg attempted to load the intel card first before the nvidia card. since intel is already used by display :0 it barfs with the drm error.
I got around this by appending "Screen" section to /etc/bumblebee/xorg.conf.nvidia and force it to use the "DiscreteNvidia" device as defined at the top of this config file:
Identifier "Default Screen"