Lenovo Thinkpad T495

Lenovo Thinkpad T495 is a business notebook based on 2nd generation of AMD Ryzen™ processors with Radeon™ Vega graphics, supporting AMD FreeSync™, and delivering up to 14.9 hours of battery life.

Hardware
Lenovo Thinkpad T495 specification:

CPU and its features:

List of PCI devices:

List of USB devices:

GRUB settings
Edit/update the following line in the following file:

Unable to write to IOMMU
Sometimes (most of the time) I am getting the following kernel message when booting the system:

Later, in the kernel log, one can find the following line:

It seems that IOMMU works just fine and the first message is a result of a premature initialization of the IOMMU system. According to other reports found on the internet, it can be ignored. Still, it pollutes the screen during a silent boot process.