Nvidia driver works but the monitor stays black with No Signal error

Void Linux upgrade caused monitor to show "No Signal".

Bare in mind that if you manually added the fix, the upgrade can revert your change.

TL;DR

After a Void Linux upgrade, the monitor showed "No Signal" even though the NVIDIA driver loaded correctly and nvidia-smi detected the GPU. The issue was that NVIDIA DRM modesetting was not enabled, causing DRM display connectors (DisplayPort/HDMI) to not be exposed under /sys/class/drm/.

Add the following kernel parameter to Grub config file /etc/default/grub.

GRUB_CMDLINE_LINUX_DEFAULT="nvidia-drm.modeset=1"

Then regenerate the GRUB configuration and reboot.

sudo grub-mkconfig -o /boot/grub/grub.cfg
sudo reboot

Symptoms

• Monitor showed "No Signal"
• NVIDIA driver loaded successfully
• nvidia-smi worked and detected the RTX 3080 Ti
• DKMS modules were built for the running kernel
• No Nouveau module was loaded

lsmod | grep -E 'nvidia|nouveau'

Output:

nvidia_drm
nvidia_modeset
nvidia

Investigation

The NVIDIA driver appeared healthy:

nvidia-smi

Output:

NVIDIA GeForce RTX 3080 Ti             Disp.A Off

The GPU was detected correctly, but no display outputs were active.

Next, I inspected the DRM devices:

ls -l /sys/class/drm/

Output:

card0
renderD128
version

Expected connector entries (such as below) were missing.

card0-DP-1
card0-DP-2
card0-HDMI-A-1

This indicated that the NVIDIA DRM layer was not exposing any display connectors to the kernel.

Cause

The running kernel command line was:

cat /proc/cmdline

Output:

BOOT_IMAGE=/boot/vmlinuz-6.18.34_1 root=UUID=d41c9246-090e-47f4-af08-8ea490e6b06b ro loglevel=4

nvidia-drm.modeset=1 parameter was missing after the upgrade.

Without NVIDIA DRM modesetting enabled, the proprietary driver loaded successfully but failed to expose display connectors, causing the monitor to lose signal.

Fix the issue

Edit /etc/default/grub and add GRUB_CMDLINE_LINUX_DEFAULT="nvidia-drm.modeset=1".

Then regenerate the GRUB configuration and reboot.

sudo grub-mkconfig -o /boot/grub/grub.cfg
sudo reboot

Notes

• NVIDIA DKMS modules were correctly built for the running kernel.
• The NVIDIA kernel modules loaded successfully.
• nvidia-smi worked as expected.
• No Nouveau modules were active.
• The missing DRM connector entries were the key clue that pointed to a modesetting issue.

This diagnosis should be considered a likely root cause until confirmed by successfully booting with nvidia-drm.modeset=1.