[3.19.y-ckt stable] Patch "drm/i915: apply the PCI_D0/D3 hibernation workaround everywhere on pre GEN6" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    drm/i915: apply the PCI_D0/D3 hibernation workaround everywhere on pre GEN6

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt8.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

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>From 70080d1a6cd454a054990e91f1947d131405b5c1 Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak at intel.com>
Date: Tue, 30 Jun 2015 17:06:47 +0300
Subject: drm/i915: apply the PCI_D0/D3 hibernation workaround everywhere on
 pre GEN6

commit 54875571bbfde00fc63741715c531cbb5246c3b2 upstream.

commit da2bc1b9db3351addd293e5b82757efe1f77ed1d
Author: Imre Deak <imre.deak at 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 at 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 at gmail.com>
Reported-by: Dirk Griesbach <spamthis at freenet.de>
Reported-by: Pavel Machek <pavel at ucw.cz>
Reported-by: Mikko Rapeli <mikko.rapeli at iki.fi>
Tested-by: Mikko Rapeli <mikko.rapeli at iki.fi>
Reported-by: Paul Bolle <pebolle at tiscali.nl>
Signed-off-by: Imre Deak <imre.deak at intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 34d0e58..902bd64 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -637,15 +637,18 @@ static int i915_drm_suspend_late(struct drm_device *drm_dev, bool hibernation)

 	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;
--
1.9.1