Created attachment 138824 [details]
dmesg from kernel 4.15 with cik_support=1 dc=1 dc_log=1

Going back to kernel 4.15 makes no difference for me. I think that the issue
reported in comment 8 is different and should be reported in a separate bug.

Though I noticed that in 4.15, dc_log=1 gives more output than in 4.16 where it
doesn't make any difference.