Hmm, I notice these errors:

[    2.050887] [drm:radeon_acpi_init [radeon]] Call to ATCS verify_interface
failed: -5
[    2.050994] [drm:radeon_acpi_init [radeon]] Call to ATIF verify_interface
failed: -5

which I think are ACPI calls, it might be worth checking your BIOS/EFI is up to
date and if that doesn't fix things maybe play around with the acpi_osi=
options