https://bugzilla.kernel.org/show_bug.cgi?id=201183
--- Comment #7 from Nicholas Kazlauskas (nicholas.kazlauskas@amd.com) --- It doesn't look like your log buffer was large enough to hold the full log.
A log with drm.debug=4 might have enough information to work off of. The other option is reposting the drm.debug=6 log with a large log buffer size in the kernel config.