https://bugs.freedesktop.org/show_bug.cgi?id=108521
--- Comment #31 from Alex Deucher alexdeucher@gmail.com --- (In reply to Robert Strube from comment #30)
Hi Alex,
Thanks for the reply. I wanted to clarify an important point: When I disabled PM completely and ACPI completely, I did not see any PCI resource issues AND the eGPU initialized successfully.
acpi=off apm=off amdgpu.dpm=0 amdgpu.aspm=0 amdgpu.runpm=0 amdgpu.bapm=0
the only relevant items here are acpi=off and amdgpu.dpm=0. Did you test them independently or just together? setting dpm=0 is irrelevant if acpi=off since there will be no resource restrictions. You need to test them independently.
I've been working with another user that has the exact same system (XPS 9575) and an RX 580 and is having the same issues. He was actually able to get the eGPU initialized by passing in PCI=noacpi rather than completely disabling ACPI as a whole. I'll double check with him to see if he can post his dmesg log - because I'm not sure if the PCI resource issues are present under those circumstances.
looks like the same issue as yours. PCI resources not getting assigned.