https://bugs.freedesktop.org/show_bug.cgi?id=111261
--- Comment #6 from Fab Stz fabstz-it@yahoo.fr --- The issue seems to be related to these calls in file amdgpu-19.30-855429/amd/display/amdgpu_dm/amdgpu_dm.c
twice: kcl_drm_dp_cec_unset_edid(&aconnector->dm_dp_aux.aux);
once: kcl_drm_dp_cec_set_edid(&aconnector->dm_dp_aux.aux, aconnector->edid);
If I delete them the display works also with 19.30