Recently, Ubuntu 17.04 doesn't recognize the secondary graphic card installed on my laptop by manufacturer. The graphic card model is Nvidia Geforce 720M.
Here is the output of commands I ran to diagnose the problem:
$ lspci -vnnn | perl -lne 'print if /^\d+\:.+(\[\S+\:\S+\])/' | grep VGA
00:02.0 VGA compatible controller [0300]: Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09) (prog-if 00 [VGA controller])
$ lspci -k | grep -EA3 'VGA|3D|Display'
00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09)
Subsystem: Acer Incorporated [ALI] 3rd Gen Core processor Graphics Controller
Kernel driver in use: i915
Kernel modules: i915
--
01:00.0 3D controller: NVIDIA Corporation GF117M [GeForce 610M/710M/810M/820M / GT 620M/625M/630M/720M] (rev a1)
Subsystem: Acer Incorporated [ALI] GeForce GT 720M
Kernel modules: nvidiafb, nouveau, nvidia_340
02:00.0 Ethernet controller: Broadcom Limited NetXtreme BCM57786 Gigabit Ethernet PCIe (rev 01)
$ sudo nvidia-detector
none
$ nvidia-settings
ERROR: Unable to find display on any available system
$ optirun glxinfo|egrep "OpenGL vendor|OpenGL renderer"
[ 1142.796148] [ERROR]Cannot access secondary GPU - error: Could not load GPU driver
[ 1142.796180] [ERROR]Aborting because fallback start is disabled.
$ echo $XDG_SESSION_TYPE
wayland
echo $XDG_SESSION_TYPE
to your question – Charles Green Nov 28 '17 at 17:14