Comment # 6 on bug 1055493 from Takashi Iwai

I still could reproduce the original issue on Dell laptop with Skylake on 4.12
vanilla kernel.  Since the hackish fix patch for SLE12 was removed on SLE15
code base, the issue happened on SLE15, too.

Then I noticed that 4.13 seems working, and the bisection pointed to a few
DP-MST patches.  So these fix patches are merged to SLE15 (on the way, now in
pull request).

Though, these fixes don't look effective on 4.4.x, especially because only two
of four commits are applicable.  In anyway, I prepared a Leap 42.2 test kernel
in OBS home:tiwai:bnc1055493 repo.

No matter whether the test kernel works or not, please test the upstream 4.12.x
and 4.13 kernels to see whether we're tracking the same problem.  Your chip is
different from mine, so it might be triggered by a different cause.