I helped this user for several hours in #ubuntu IRc support diagnosing this issue.

It's:

DMI: HP HP Notebook/81EC, BIOS F.23 12/01/2016

with integrated Intel and AMD GPUs.

We fetched the latest firmware for amdgpu/raven* from the linux-firmware repo. We tested the stock Ubuntu v4.13 kernel and the latest mainline build of v4.15-rc8. 

In neither case would the amdgpu module bind to the GPU despite it declaring a matching modalias. The radeon driver did bind. We blacklisted radeon but could not get amdgpu to bind. There was nothing in the kernel log to indicate amdgpu even 'looked' at the GPU.


gopal@gopal-HP-Notebook:~$ lspci -nnvvk -d ::0380 
01:00.0 Display controller [0380]: Advanced Micro Devices, Inc. [AMD/ATI] Sun XT [Radeon HD 8670A/8670M/8690M / R5 M330 / M430 / R7 M520] [1002:6660] (rev 83)
	Subsystem: Hewlett-Packard Company Sun XT [Radeon HD 8670A/8670M/8690M / R5 M330] [103c:81ec]
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
	Latency: 0, Cache Line Size: 64 bytes
	Interrupt: pin A routed to IRQ 126
	Region 0: Memory at 90000000 (64-bit, prefetchable) [size=256M]
	Region 2: Memory at b1300000 (64-bit, non-prefetchable) [size=256K]
	Region 4: I/O ports at 4000 [size=256]
	Expansion ROM at b1340000 [disabled] [size=128K]
	Capabilities: <access denied>
	Kernel driver in use: radeon
	Kernel modules: radeon, amdgpu


dmesg log (when radeon driver binds) @ https://paste.ubuntu.com/26432143/

Per https://wiki.archlinux.org/index.php/AMDGPU:

You'll need to add amdgpu.si_support=1 radeon.si_support=0 to your kernel commandline, since otherwise amdgpu will just ignore it.

(Per https://en.wikipedia.org/wiki/AMD_Radeon_Rx_300_series it looks like GCN 1st gen, aka SI, which makes sense with radeon using it by default. Definitely no raven)

@Bas: Thanks for the link and clarification of the hardware type. Issue started with the question on how to install the raven firmware and developed from there so I assumed the GPU required it, not being familiar with AMD GPUs.