https://bugzilla.kernel.org/show_bug.cgi?id=206393
--- Comment #4 from Bjoern Franke (bjo@nord-west.org) --- It's a regression, it did not appear with 5.4.15. The error message "[ 1.549880] [drm:dm_helpers_parse_edid_caps [amdgpu]] *ERROR* Couldn't read SADs: -2" at the beginning also does not appear with 5.4.15.
I will try to bisect it (my last bisecting is 8 years ago).