da2bc1b9db3351addd293e5b82757efe1f77ed1d breaks hibernation was Re: 4.1-rc7, thinkpad X60: platform mode hibernation does very wrongthing

Pavel Machek
2015-06-17T15:18:03Z

Hi!

> And this all reminded me of https://lkml.org/lkml/2015/3/18/133 . So I
> think that's another system not covered by commit ab3be73fa7b4
> ("drm/i915: gen4: work around hang during hibernation").

Yes, another system broken by

commit da2bc1b9db3351addd293e5b82757efe1f77ed1d
Author: Imre Deak <imre.deak@intel.com>
Date: Thu Oct 23 19:23:26 2014 +0300

drm/i915: add poweroff_late handler

The suspend_late handler saves some registers and powers off the
device,
so it doesn't have a big overhead. Calling it at S4
poweroff_late time
makes the power off handling identical to the S3 suspend and
S4 freeze
handling, so do this for consistency.

And no, adding another system to the "blacklist" is a not good idea,
because we know there are other broken systems out there. Can we
revert da2bc1b9db3351addd293e5b82757efe1f77ed1d, please? Consistency
is nice, but not having regressions is even nicer.
Pavel

PS: Now I have real Linus and fake Linus on the Cc list. Or maybe two
real Linuses, its hard to tell.