This sounds like exactly the problem I have. Newer Linux kernels load different microcode for my 380, which doesn't work. There are two ways to work around this if it's the same problem: 1) Revert to Linux 4.8 or earlier 2) Replace the newer firmware file with the older one: cp /lib/firmware/amdgpu/tonga_smc.bin /lib/firmware/amdgpu/tonga_k_smc.bin If you try option 2, make a backup of the original tonga_k_smc.bin first.