https://bugs.freedesktop.org/show_bug.cgi?id=93217
--- Comment #30 from Alex Deucher alexdeucher@gmail.com --- (In reply to Mike Lothian from comment #29)
Would you like me to try re-enabling pcie dpm and use the new kernel parameters in drm-next-4.6-wip?
Yes, can you see what combinations of pcie_gen_cap and pcie_lane_cap help? See amd_pcie.h.
pcie_gen_cap: bits 31:16 define the gen speeds supported by the platform (e.g., the motherboard). Setting it to CAIL_PCIE_LINK_SPEED_SUPPORT_GEN3 (0x00040000) would indicate that the motherboard only supports gen3 (not gen 2 or 1). bits 15:0 define the pcie speeds supported by the GPU itself. Setting this to CAIL_ASIC_PCIE_LINK_SPEED_SUPPORT_GEN3 (0x00000004) means the asic only supports gen 3.
pcie_lane_cap: bits 31:16 define the link width supported by the platform.