Ubuntu 20.04 GeForce MX150 couldn't communicate with the NVIDIA driver

I’m using Ubuntu20.04. I have installed the available graphics driver nvidia-driver-460.
Now I can open Nvidia settings. But drivers are still not loaded. I’m not able to use the Nvidia graphics card.

This error comes when I run nvidia-smi:

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 have already tried suggested methods but no luck.

Kindly help me.
The log file is attached.
nvidia-bug-report.log.gz (1005.3 KB)

The log shows:

Jan 21 20:15:20 sudesh-ubuntu20-04 kernel: [23546.457489] nvidia-nvlink: Nvlink Core is being initialized, major device number 236
Jan 21 20:15:23 sudesh-ubuntu20-04 kernel: [23548.679755] NVRM: This is a 64-bit BAR mapped above 4GB by the system
Jan 21 20:15:23 sudesh-ubuntu20-04 kernel: [23548.679755] NVRM: BIOS or the Linux kernel, but the PCI bridge
Jan 21 20:15:23 sudesh-ubuntu20-04 kernel: [23548.679755] NVRM: immediately upstream of this GPU does not define
Jan 21 20:15:23 sudesh-ubuntu20-04 kernel: [23548.679755] NVRM: a matching prefetchable memory window.
Jan 21 20:15:23 sudesh-ubuntu20-04 kernel: [23548.679760] NVRM: This may be due to a known Linux kernel bug. Please
Jan 21 20:15:23 sudesh-ubuntu20-04 kernel: [23548.679760] NVRM: see the README section on 64-bit BARs for additional
Jan 21 20:15:23 sudesh-ubuntu20-04 kernel: [23548.679760] NVRM: information.
Jan 21 20:15:23 sudesh-ubuntu20-04 kernel: [23548.695048] NVRM: The NVIDIA probe routine failed for 1 device(s).
Jan 21 20:15:23 sudesh-ubuntu20-04 kernel: [23548.695051] NVRM: None of the NVIDIA devices were initialized.

Check for a bios option “Above 4G decoding” and enable it.

The “above 4G decoding” option is only necessary for Tesla type gpus, for mobile chips the error message about the BAR is terribly misleading, it just means the gpu is turned off (all pci config space bytes are FF).
Please check if you have bbswitch installed and uninstall it. If that doesn’t help, please create a new nvidia-bug-report.log instantly after a fresh boot. In the attached one the error message flooded the log and pushed out the actual info.

There isn’t such an option in my PC’s bios.

Thanks, @generix. It’s resolved now. I purged all the packages related to nvidia-drivers including bbswitch and reinstalled them with sudo ubuntu-drivers autoinstall.