HDMI audio lost function after the dGPU did runtime suspend. (AMD RX 580)

[Leon Liao]

On Dell Precision 7740, after installed amdgpu-pro 19.10-793418, the HDMI audio will lose function after the dGPU did runtime suspend.

How to check the AMD dGPU is in runtime suspend:
 $ lspci -s 01:00.0 -xxvv
When the AMD dGPU is in runtime suspend, all of the registers will be 0xf.

Release: 18.04 LTS
kernel: 4.15.0-1037-oem
amdgpu-pro: 19.10-793418

[Leon Liao (lihow731)]

There is a workaround solution to avoid this bug.
It is to disable the amdgpu runtime suspend.
Just add amdgpu.runpm=0 on the kernel command line.

[Kent Lin (kent-jclin)]

5.0 Kernel + following patched [1] + AMD 19.30 driver [2], the issue is fixed.

[1] Takashi Iwai's sound component support patch for AMDGPU
- https://patchwork.kernel.org/patch/10540417/

[2] AMD 19.30 driver: https://www.amd.com/en/support/kb/release-notes/rn-amdgpu-unified-linux