Brightness level blocked to maximum, nvidia xconfig "Unable to find any GPUs in the system"

Hi !
Hello, I recently bought a new computer.
I installed a dual boot windows Ubuntu 20.
My computer is an HP omen O15.
But I have a very disturbing brightness problem. This one is blocked at the maximum, and I cannot lower it. When I try :

xrandr

I got

xrandr: Failed to get size of gamma for output default
Screen 0: minimum 1920 x 1080, current 1920 x 1080, maximum 1920 x 1080
default connected primary 1920x1080+0+0 0mm x 0mm
   1920x1080     77.00* 

When I try

nvidia-smi

I got

NVIDIA-SMI has failed because it couldn't communicate with the NVIDIA driver. Make sure that the latest NVIDIA driver is installed and running.

I tried

nvidia-xconfig

I got

Using X configuration file: "/etc/X11/xorg.conf".
VALIDATION ERROR: Data incomplete in file /etc/X11/xorg.conf.
                  Device section "Device0" must have a Driver line.
WARNING: Unable to parse X.Org version string.
Package xorg-server was not found in the pkg-config search path.
Perhaps you should add the directory containing `xorg-server.pc'
to the PKG_CONFIG_PATH environment variable
No package 'xorg-server' found
ERROR: Unable to find any GPUs in the system.
ERROR: Unable to write to directory '/etc/X11'.
lspci | grep VGA

Give me :

01:00.0 VGA compatible controller: NVIDIA Corporation GA106M [GeForce RTX 3060 Mobile / Max-Q] (rev a1)
06:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Cezanne (rev c5)

nvidia-bug-report.log.gz (131.6 KB)
You can find my nvidia bug report in attachment.
Any idea? I have already gone through the other topics and there proposed solution bug none seems to solve my prbl. Thank you in advance !!

The internal panel and thus its brigtness is driven by your amd igpu which is defunct due to you running an older, non-standard kernel. So also the nvidia driver doesn’t compile. Please either switch back to the stock 5.15 kernel or upgrade the kernel using the liquorix ppa.

Hello Generix, thank you for your response, I tried to install the liquorix kernel following this tuto. But after installing this kernel I can’t open a session, because after starting it, it reboot endlessly.
So I boot it in recovery mode, commandline, and I found in /var/log/boot.log that :
Failed to start Load/Save Screen Backlight Brightness of backlight.acpi_video0. See systemctl status systemd_backligh@backlight:acpi_video0.service for details
I tried systemctl status of this service, but there isn’t lot of information, (We just know that the service is active but it excited with error code. )
Have you any idea of this error?
Thanks in advance.

Sometimes systemd detects wrong backlight handlers so on boot it tries for a long time restoring it which delays boot by ~ 2 minutes. Please simply disable the unit. Afterwards, please create a new nvidia-bug-report.log.

Hy, thanks for your response.
I disabled the backlight Brightness, but it didn’t change anything. Booting on liquorix kernel reboot endlessly, so I tryed to mask the service, but the problem persist.
I drive into recovery mode (root cml), and I make a nvidia-bug-report.
You can find it in attachment
nvidia-bug-report.log (380.3 KB)

Please delete /etc/X11/xorg.conf

Okay, I delete it and reboot into recovery mode.
Here is the nvidia bug report.
nvidia-bug-report.log (380.9 KB)

Please boot to normal mode at least once.

I’ve already done it.
(Before booting in rescue mode) i tried in normal mode and because it failed I used rescue mode for the last nvidi-bug-report.

Can you reach a text console (ctrl+alt+f4) after booting normal? If so, please create a new nvidia-bug-report.log.
If that doesn’t work, please enable log persistence
https://www.golinuxcloud.com/enable-persistent-logging-in-systemd-journald/
Then boot normal once, reboot to recovery, then run
sudo journalctl -b-1 >journal.txt
to get the logs from previous boot.

Ok thanks, I tried to reach the console but it behave the same way.
Here is the journalctl -b-1 runned in recovery mode just after the normal boot. So it contains the normal boot logs.
journal.txt (115.1 KB)