https://bugs.freedesktop.org/show_bug.cgi?id=109135
--- Comment #18 from Alex Deucher alexdeucher@gmail.com --- (In reply to rmuncrief from comment #17)
Yes, As I said in the beginning if you don't set amdgpu.dpm=1 the system boots but resume doesn't work. I presume it's because power management isn't working. All kernels before 4.19.x work great, and have no problem with resume so long as dpm is enabled.
dynamic power management is always enabled by default. the only way to disable it is to set dpm=0. dpm=1 either does nothing or changes the implementation used in the driver depending on the asic. You shouldn't set dpm= unless you are debugging something. For your asic, kernels 4.18 and older the default was the original dpm implementation; setting dpm=1 used the newer powerplay code. For kernel 4.19 and newer, the default implementation switched to the newer powerplay code and setting dpm=1 switched back to the older implementation. So removing dpm=1 is correct for 4.19 and newer. Can you elaborate on the resume issue?