commit da2bc1b9
Author: Imre Deak <imre.deak@intel.com>
Date:   Thu Oct 23 19:23:26 2014 +0300

    drm/i915: add poweroff_late handler

introduced a regression on old platforms during hibernation. A workaround was
added in

commit ab3be73f
Author: Imre Deak <imre.deak@intel.com>
Date:   Mon Mar 2 13:04:41 2015 +0200

    drm/i915: gen4: work around hang during hibernation

using an explicit blacklist for the GENs/BIOS vendors where the issue was
reported. Later there we had reports of the same failure on platforms not on
this list.

To my best knowledge the correct thing to do is still to put the device to PCI
D3 state during hibernation, see [1] and [2] for the reasons. This also aligns
with our future plans to unify more the runtime and system suspend/resume
paths. Since an exact blacklist seems to be impractical (multiple GENs and
BIOS vendors are affected) apply the workaround on everything pre GEN6.

[1] http://lists.freedesktop.org/archives/intel-gfx/2015-February/060710.html
[2] https://lkml.org/lkml/2015/6/22/274

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=95061Reported-by: Ilya Tumaykin <itumaykin@gmail.com>
Reported-by: Dirk Griesbach <spamthis@freenet.de>
Reported-by: Pavel Machek <pavel@ucw.cz>
Reported-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Tested-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Reported-by: Paul Bolle <pebolle@tiscali.nl>
CC: stable@vger.kernel.org
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>