I'm having issues using hardware accelerated graphics on my AMD Ryzen 5 3400G with A300M-STX mainboard and A300 chipset by ASRock.

That's the AMD Ryzen 5 3400G with Radeon Vega Graphics (family: 0x17, model: 0x18, stepping: 0x1)

When attaching an UHD (4k) monitor over the DisplayPort, everything works as expected as long as I am running an older kernel that doesn't support the APU video hardware. E.g. 4.15 or 4.18.

When I use 5.0, 5.1 or 5.2 kernel, the _same display connection that worked fine before_ doesn't work anymore. The image keeps disappearing, shaking, distorting and creating green pixel noise, as if the cable is bad quality.

When starting those same kernels with `nomodeset` from GRUB, the image is stable again, but the hardware acceleration is disabled.

HDMI works fine on a HD display (1920x1080) but also no picture on UHD.

HWE Kernel 5.0.0.20.21~18.04.1 does have hardware rendering, but shows the following:

```
[    1.296083] kfd kfd: DID 15d8 is missing in supported_devices
[    1.296084] kfd kfd: kgd2kfd_probe failed
```

So I used Ukuu to install 5.2.0-RC7.

```
$ uname -a
Linux abu 5.2.0-050200rc7-generic #201906300430 SMP Sun Jun 30 04:32:31 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

$ lspci | grep -i vga
04:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Picasso (rev c8)

$ glxinfo  | grep Extended -A11
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: X.Org (0x1002)
    Device: AMD RAVEN (DRM 3.32.0, 5.2.0-050200rc7-generic, LLVM 8.0.1) (0x15d8)
    Version: 19.2.0
    Accelerated: yes
    Video memory: 2048MB
    Unified memory: no
    Preferred profile: core (0x1)
    Max core profile version: 4.5
    Max compat profile version: 4.5
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.2

$ dmesg | grep -i amdgpu | grep -v ring
[    1.202002] [drm] amdgpu kernel modesetting enabled.
[    1.202142] amdgpu 0000:04:00.0: remove_conflicting_pci_framebuffers: bar 0: 0xe0000000 -> 0xefffffff
[    1.202143] amdgpu 0000:04:00.0: remove_conflicting_pci_framebuffers: bar 2: 0xf0000000 -> 0xf01fffff
[    1.202144] amdgpu 0000:04:00.0: remove_conflicting_pci_framebuffers: bar 5: 0xfcc00000 -> 0xfcc7ffff
[    1.202146] fb0: switching to amdgpudrmfb from EFI VGA
[    1.202220] amdgpu 0000:04:00.0: vgaarb: deactivate vga console
[    1.202253] amdgpu 0000:04:00.0: enabling device (0006 -> 0007)
[    1.202474] amdgpu 0000:04:00.0: VRAM: 2048M 0x000000F400000000 - 0x000000F47FFFFFFF (2048M used)
[    1.202475] amdgpu 0000:04:00.0: GART: 1024M 0x0000000000000000 - 0x000000003FFFFFFF
[    1.202476] amdgpu 0000:04:00.0: AGP: 267419648M 0x000000F800000000 - 0x0000FFFFFFFFFFFF
[    1.202577] [drm] amdgpu: 2048M of VRAM memory ready
[    1.202578] [drm] amdgpu: 3072M of GTT memory ready.
[    1.509190] fbcon: amdgpudrmfb (fb0) is primary device
[    1.559664] amdgpu 0000:04:00.0: fb0: amdgpudrmfb frame buffer device
[    1.584215] [drm] Initialized amdgpu 3.32.0 20150101 for 0000:04:00.0 on minor 0
```

Tested on Linux Mint 19.1.