AMD Athlon 300U laptop fails DRM init Linux 5.4.7 (and 5.4.8)
I am running Arch Linux on my Acer Swift 3 (AMD Athlon 300U). With the two most recent stable kernel releases, I am getting DRM initialization failures, which cause the system to be unusable (i.e. can not use the system because it hangs). I was once able to get a dmesg from a failed boot, and am attaching the relevant portion of it (more can be provided if this is not enough). This laptop has been stable since I purchased it (early October 2019) with new kernel releases from Arch until now.
The issue is very clear in the attached log (notworking-5.4.8.txt). It starts with the line: [ 39.306902] [drm:atom_op_jump [amdgpu]] ERROR atombios stuck in loop for more than 5secs aborting
Also interesting are the lines: [ 3.234653] AMD-Vi: Completion-Wait loop timed out
which show up only in the 5.4.7+ kernel versions. In the Linux kernel versions 5.4.6 and prior, this system runs great (see attached file working-5.4.6.txt)
I am glad to help troubleshoot this, please let me know if you need more information.