Lenovo ThinkPad L14 Problem booting Ubuntu 20.10 (Kernel 5.8) with Ryzen 7 Pro 4750U

I got my ThinkPad L14 this year (2020)
When I upgraded my Ubuntu from 20.04 to 20.10 I encountered blank screen.

In booting logs I saw this error:

AMD-Vi: Unable to read/write to IOMMU perf counter

and inspired by this Stackoverflow answer https://stackoverflow.com/questions/62827591/amd-vi-unable-to-read-write-to-iommu-coun-problem-loading-x-509-certificate/63112560

I did the following:

• in your GRUB boot menu select Advanced Ubuntu
• select your previous (working) kernel version, mine was 5.4
• log into Ubuntu
• edit GRUB sudo vim /etc/default/grub
• change this line GRUB_CMDLINE_LINUX="iommu=soft" and save the change
• run sudo update-grub
• restart and select your updated Ubuntu with kernel version 5.8

And it works!