Greetings mighty developers :)
im reporting a bug in which the aforementioned kernels when compiled
with the AMDGPU driver fail to properly function in the presence of a
Tonga PRO card.  The driver is loaded, the cards fans then spin up to
100% and the system becomes unresponsive to ctrl+alt+del.  additionally
no graphics are displayed.  it is all sound and fury.

debug info below.  please feel free to ask for more as needed.

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc.
[AMD/ATI] Tonga PRO [Radeon R9 285/380] (rev f1)

Linux cypher 4.8.14-gentoo #6 SMP Sun Feb 12 13:42:53 PST 2017 x86_64
AMD FX(tm)-6100 Six-Core Processor AuthenticAMD GNU/Linux

AMD related kernel settings:
# CONFIG_X86_AMD_PLATFORM_DEVICE is not set
CONFIG_CPU_SUP_AMD=y
CONFIG_X86_MCE_AMD=y
# CONFIG_PERF_EVENTS_AMD_POWER is not set
CONFIG_MICROCODE_AMD=y
CONFIG_AMD_NUMA=y
# CONFIG_X86_AMD_FREQ_SENSITIVITY is not set
CONFIG_AMD_NB=y
CONFIG_PATA_AMD=y
CONFIG_NET_VENDOR_AMD=y
# CONFIG_AMD8111_ETH is not set
# CONFIG_AMD_PHY is not set
# CONFIG_HW_RANDOM_AMD is not set
# CONFIG_I2C_AMD756 is not set
# CONFIG_I2C_AMD8111 is not set
CONFIG_AGP_AMD64=y
CONFIG_DRM_AMDGPU=m
CONFIG_DRM_AMDGPU_CIK=y
CONFIG_DRM_AMDGPU_USERPTR=y
CONFIG_DRM_AMDGPU_GART_DEBUGFS=y
CONFIG_DRM_AMD_POWERPLAY=y
# CONFIG_DRM_AMD_ACP is not set
CONFIG_AMD_IOMMU=y
# CONFIG_AMD_IOMMU_V2 is not set
# CONFIG_MCE_AMD_INJ is not set
CONFIG_KVM_AMD=y