On Tue, 2016-07-19 at 10:59 +0200, Willy Tarreau wrote:

On Tue, Jul 19, 2016 at 08:41:21AM +0000, Joakim Tjernlund wrote:

quoted

quoted

Did you try it or at least the kernel which contains it ? It is important

No I haven't. I myself do not have such a laptop so I must find someone that does
and willing to test stuff for me(I maintain our Linux DE used for in-house development)
All I can say for sure is that 4.1.x works and 4.4.x does not :(

OK that's already a good indication.

(...)

quoted

Yes I get that but I figured that a upstream commit that is marked:
ï¿œCc: [off-list ref] # v4.2+
already was approved for stable and it would find its way into all relevant branches.

Indeed it could be one candidate, so if you can afford to wait for a
next release to see if it fixes your problem that's the easiest way.
Otherwise you'll have to bisect either between 4.1 and 4.4 to find
which one broke, or to test mainline to see if it's fixed again. But
given that it was a regression, it's likely that someone else will
notice it and propose a fix (possibly the one above).
ï¿œ

Yes, plenty of people have similar has a problem but Intel devs have had hard time
finding the bugs.

Greg, could push your mail queue so I can compare with upstream?

Seems like this patch has been lost though:
ￜ[PATCH stable-4.4] drm/i915: Update CDCLK_FREQ register on BDW after changing cdclk frequency

ï¿œJocke