Comment # 8 on bug 1141720 from Takashi Iwai

So, one obvious difference is that Ubuntu is 5.0.x while TW is 5.1.x.

I'd try at first the latest upstream 5.2.x from OBS Kernel:stable repo (maybe
TW gets already that version).  If the problem persists, you can try 5.0.x TW
kernel in OBS home:tiwai:kernel:5.0 repo.

If 5.0.x works and later version doesn't, it's a kernel regression and should
be tracked by the upstream.

OTOH, if TW 5.0.x kernel doesn't work, it's likely a difference of kernel
configuration.  For example, Ubuntu seems having the cherrytrail pinctrl driver
built-in while TW has it as a module.