Comment # 29 on bug 1159882 from Andrei Borzenkov

(In reply to Miroslav Bene�� from comment #26)
> It is not surprising to see it strikes 15.2 too. The original bug was
> reported against 5.3 kernel, which is in 15.2. It got somehow fixed in 5.6
> at the latest. We may try to find the fixes but they may be too intrusive to
> backport.
> 

The commit 2c012a4ad1a2cd3fb5a0f9307b9d219f84eda1fa mentioned in comment #14
was effectively removed in commit b91ac374346ba206cfd568bb0ab830af6b205cfd
which went into 5.5. I actually observed quite similar symptoms in Ubuntu 18.04
as soon as it bumped HWE kernel to 5.3 and had to install 5.5 (5.4 had the same
issue).

I do not know if b91ac374346ba206cfd568bb0ab830af6b205cfd alone can be back
ported but may be 2c012a4ad1a2cd3fb5a0f9307b9d219f84eda1fa could be reverted as
this is what happened in upstream anyway.