The nvidia-drm.modset=1 parameter should still work (does for me). Are you sure the first example (using clr-boot-manager) doesn't work for you?
Since you seem to be using GRUB, have you tried manually inserting it on boot (select the GRUB entry, press "E", add the parameter to the line of parameters, press CTRL+X to save and boot)
Tearing 940MX. There has never been such a thing and here it is again.
Staudey Hmm... Manually adding a parameter at boot helped to get rid of tearing. Strange. Why then, when modifying GRUB through a file, does it not work for me? Am I really doing everything right?
Is there any other way to add a parameter to GRUB? I think adding via /etc/default/grub and generating a new file /boot/grub/grub.cfg doesn't work.
Hmm, not sure why the clr-boot-manager method doesn't work for me. It does it just fine for me, and that's on a system that uses GRUB too.
Do you get any weird errors when running sudo clr-boot-manager update ?
Staudey No, there are no errors as such, and the download is performed without problems. It is strange that when the GRUB configuration is modified, it is not updated. Why?
alexanderzhirov I was talking about the proper clr-boot-manager method, i.e.
echo "nvidia-drm.modeset=1" | sudo tee /etc/kernel/cmdline.d/50-nvidia-drm.conf
sudo clr-boot-manager updateI wouldn't start modifying GRUB directly, as that should be handled by clr-boot-manager too
I added an entry immediately to /boot/grub/grub.cfg and it started working. But this is the wrong method, since when updating the kernel or GRUB itself, the boot configuration will be updated. So I think we should solve the problem anyway.
@Staudey 
Do I need to create this manually and will it be the right solution?
alexanderzhirov Could it be that the /etc/kernel/cmdline.d/ folder doesn't exist on your system? This would cause that error and I assume prevent the config file from being created.
Staudey Yes, I understand that. The directory does not exist. I just don't understand in which case it should exist for me? If it doesn't exist, should I manually create a directory with a configuration file and would this be the right solution to rebuild GRUB? Or do I need to install any additional packages? That's what I meant.
alexanderzhirov I'm just double-checking because our instructions won't work if that folder doesn't exist, which is not ideal.
Creating that directory and then running the instructions again should make it work, yes. The right way to interact with GRUB is via clr-boot-manager.
Staudey It turned out to achieve the result after creating a branch directory and a configuration file:
sudo mkdir -p /etc/kernel/cmdline.d
echo "nvidia-drm.modeset=1" | sudo tee /etc/kernel/cmdline.d/50-nvidia-drm.conf
sudo clr-boot-manager updatealexanderzhirov Thanks for reporting back!
I've already created a PR to update our instructions accordingly, so this scenario (missing folder) is accounted for.