Debugging nvidia

01.09.2020, to see all post click here.

Current state:

• kernel: 4.15.0-39
• what works: gdm starts just fine in full resolution
• what does not work: after logging the screen restarts a few times and it returns to gdm

Investigation:

• after reboot there is a line ubuntu-vg not found
• what version of Nvidia am I running?
  • inxi -g
  • nvidia-smi
    • driver version: 415.18
    • the card is off - that is expected
• xorg.cof
  • one nvidia device
  • one monitor
    • i removed horiz and vertical sync from the secton
• dmesg:
  • there was no fail in the driver
  • nvidia was loaded
• ubuntu-drivers identifies the card correctly, does not show which driver is used

Solution:

https://askubuntu.com/questions/1048274/ubuntu-18-04-stopped-working-with-nvidia-drivers

Execute sudo nano /etc/default/grub and add the parameter nvidia-drm.modeset=1 to the line GRUB_CMDLINE_LINUX_DEFAULT. Save the change you've made and run sudo update-grub. Restart the Ubuntu operating system, and now, everything should work properly - right as expected.

Enduring troubles

rewman:~$ sudo modprobe nvidia
modprobe: ERROR: ../libkmod/libkmod-module.c:832 kmod_module_insert_module() could not find module by name='off'
modprobe: ERROR: could not insert 'off': Unknown symbol in module, or unknown parameter (see dmesg)

So this bullshit comes from nvidia aliasing things to off...

https://askubuntu.com/questions/1084829/modprobe-nvidia-throws-error-could-not-insert-off

This has solved it somehow.

So it looks like nvidia is still not loaded. Ugh this is fine for now.

Enabling nvidia:

$ cat /lib/modprobe.d/nvidia-kms.conf
# This file was generated by nvidia-prime
# Set value to 0 to disable modesetting
options nvidia-drm modeset=1

Another trial:

$ sudo cat  /var/log/gpu-manager.log
log_file: /var/log/gpu-manager.log
last_boot_file: /var/lib/ubuntu-drivers-common/last_gfx_boot
new_boot_file: /var/lib/ubuntu-drivers-common/last_gfx_boot
can't access /opt/amdgpu-pro/bin/amdgpu-pro-px
Looking for nvidia modules in /lib/modules/4.15.0-43-generic/updates/dkms
Found nvidia module: nvidia-uvm.ko
Looking for amdgpu modules in /lib/modules/4.15.0-43-generic/updates/dkms
Is nvidia loaded? yes
Was nvidia unloaded? no
Is nvidia blacklisted? yes
Is intel loaded? yes
Is radeon loaded? no
Is radeon blacklisted? no
Is amdgpu loaded? no
Is amdgpu blacklisted? no
Is amdgpu versioned? no
Is amdgpu pro stack? no
Is nouveau loaded? no
Is nouveau blacklisted? yes
Is nvidia kernel module available? yes
Is amdgpu kernel module available? no
Vendor/Device Id: 8086:3e9b
BusID "PCI:0@0:2:0"
Is boot vga? yes
Vendor/Device Id: 10de:1c8c
BusID "PCI:1@0:0:0"
Is boot vga? no
Skipping "/dev/dri/card0", driven by "i915"
Skipping "/dev/dri/card0", driven by "i915"
Skipping "/dev/dri/card0", driven by "i915"
Found "/dev/dri/card0", driven by "i915"
output 0:
        card0-eDP-1
Number of connected outputs for /dev/dri/card0: 1
Does it require offloading? yes
last cards number = 2
Has amd? no
Has intel? yes
Has nvidia? yes
How many cards? 2
Has the system changed? No
Intel IGP detected
Intel hybrid system
Creating /usr/share/X11/xorg.conf.d/11-nvidia-prime.conf
Setting power control to "on" in /sys/bus/pci/devices/0000:01:00.0/power/control

Most important:

Is nvidia loaded? yes
Was nvidia unloaded? no
Is nvidia blacklisted? yes