DC driver from drm-next-4.15-dc branch (upstream PR) not working

Submitted by Carlo Caione

Assigned to Default DRI bug account

Created attachment 134642
drm-next-4.15-dc log

Hardware is a new laptops that has the AMD Bristol Ridge chipset with this SoC:

AMD A10-9620P RADEON R5, 10 COMPUTE CORES 4C+6G

00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Device 9874 (rev ca)
03:00.0 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] Device 699f (rev ff)

I tried the DC support using the https://cgit.freedesktop.org/~agd5f/linux/log/?h=drm-next-4.15-dc branch and the firmware from https://people.freedesktop.org/~agd5f/radeon_ucode/polaris/ but I keep having no audio at all for HDMI.

In attachment the log.

The only way to have the DC and the HDMI audio output working is by using the branch https://cgit.freedesktop.org/~agd5f/linux/log/?h=amd-staging-4.13 and reverting both https://lists.freedesktop.org/archives/amd-gfx/2017-May/009720.html and https://cgit.freedesktop.org/~agd5f/linux/commit/?id=8f5ed2ed31944eea5c2746ec66417afac043eabd (the first one to have the HDMI output working at all, the second one to have the audio working fine).

Any idea?

Attachment 134642, "drm-next-4.15-dc log":
amdgpu_dc.log