Lenovo P15 Gen1 with RTX A4000 + Ubuntu 20.04 + Discrete Graphics > BLANK SCREEN

I just got a new ThinkPad P15 Gen1 with NVIDIA RTX A4000 graphics card and installed Ubuntu 20.04 according to the Lenovo Setup Guide. Everything went fine, but when I set the Graphics Device to Discrete , I get a black screen after the splash screen . I didn’t expect any installation problems as Lenovo suggests that Ubuntu 20.04 is officially supported. I guess there is a problem with the graphics card driver itself or how grub is set up. Did anybody else encounter this problem? Any suggestions?

NVIDIA’s 460 driver works with discrete graphics , but not 470 or 495.

I could get it to work with the NVIDIA 470 graphics driver by connecting a HDMI monitor and setting the BOOT DISPLAY DEVICE in the BIOS to HDMI . So I guess it is not the NVIDIA graphics driver. But it still does not work using just the laptop by itself.

Killing the desktop, removing the HDMI monitor and then starting the desktop again - works with just the laptop.

$: sudo init 3
$: sudo systemctl start graphical.target

Not loading the NVIDIA graphics driver until X is loaded didn’t help.

$: sudo cp /etc/default/grub /etc/default/grub.old
$: sudo nano /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT=“quiet splash” to “nomodeset”
$: sudo update-grub

Blacklisting the Nouveau graphics driver didn’t help.

$: sudo apt-get update
$: sudo apt-get upgrade
$: sudo apt-get install dkms build-essential linux-headers-$(uname -r)
$: sudo nano /etc/modprobe.d/blacklist-nouveau.conf
blacklist nouveau
blacklist lbm-nouveau
options nouveau modeset=0
alias nouveau off
alias lbm-nouveau off
$: sudo nano /etc/modprobe.d/nouveau-kms.conf
options nouveau modeset=0
$: sudo update-initramfs -u

Looks like there should be a configuration that allows to start the desktop properly.

Did you set a PRIME profile?
If not installed, install nvidia-prime. Then run sudo prime-select nvidia (then reboot), which would autoconfigure your laptop for hybrid usage.

Thanks a lot Mart for your suggestion. Yes, I was using NVIDIA prime in hybrid mode.

I have been trying different things now and also had lost the ability to run the NVIDIA driver in Hybrid mode.

Setting GRUB_CMDLINE_LINUX_DEFAULT ="quiet splash acpi=off " in /etc/default/grub made it work again , which might suggest that it is a power issue with the 4k OLED display . Note that connecting a HDMI display always works.

Then I downgraded and upgraded the BIOS and now at least I got the NVIDIA 470 driver work in Hybrid mode - without acpi=off. So maybe there were some corrupted settings in the BIOS?

I think I am going to work in hybrid mode using NVIDIA prime .

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