[PATCH 4.2 002/120] drm/i915: apply the PCI_D0/D3 hibernation workaround everywhere on pre GEN6

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Imre Deak <imre.deak@intel.com>

commit 54875571bbfde00fc63741715c531cbb5246c3b2 upstream.

commit da2bc1b9db3351addd293e5b82757efe1f77ed1d
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 ab3be73fa7b43f4c3648ce29b5fd649ea54d3adb
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=95061
Reported-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>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/i915/i915_drv.c |   15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -683,15 +683,18 @@ static int i915_drm_suspend_late(struct
 
 	pci_disable_device(drm_dev->pdev);
 	/*
-	 * During hibernation on some GEN4 platforms the BIOS may try to access
+	 * During hibernation on some platforms the BIOS may try to access
 	 * the device even though it's already in D3 and hang the machine. So
 	 * leave the device in D0 on those platforms and hope the BIOS will
-	 * power down the device properly. Platforms where this was seen:
-	 * Lenovo Thinkpad X301, X61s
+	 * power down the device properly. The issue was seen on multiple old
+	 * GENs with different BIOS vendors, so having an explicit blacklist
+	 * is inpractical; apply the workaround on everything pre GEN6. The
+	 * platforms where the issue was seen:
+	 * Lenovo Thinkpad X301, X61s, X60, T60, X41
+	 * Fujitsu FSC S7110
+	 * Acer Aspire 1830T
 	 */
-	if (!(hibernation &&
-	      drm_dev->pdev->subsystem_vendor == PCI_VENDOR_ID_LENOVO &&
-	      INTEL_INFO(dev_priv)->gen == 4))
+	if (!(hibernation && INTEL_INFO(dev_priv)->gen < 6))
 		pci_set_power_state(drm_dev->pdev, PCI_D3hot);
 
 	return 0;