[4.2.y-ckt stable] Patch "PM / sleep: Handle failures in device_suspend_late() consistently" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

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

    PM / sleep: Handle failures in device_suspend_late() consistently

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    https://git.launchpad.net/~canonical-kernel/linux/+git/linux-stable-ckt/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt12.

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

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 4e3a39f735fb5ebc0f395e719e3bc4100d1d49f4 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki at intel.com>
Date: Fri, 20 May 2016 23:09:49 +0200
Subject: PM / sleep: Handle failures in device_suspend_late() consistently

commit 3a17fb329da68cb00558721aff876a80bba2fdb9 upstream.

Grygorii Strashko reports:

 The PM runtime will be left disabled for the device if its
 .suspend_late() callback fails and async suspend is not allowed
 for this device. In this case device will not be added in
 dpm_late_early_list and dpm_resume_early() will ignore this
 device, as result PM runtime will be disabled for it forever
 (side effect: after 8 subsequent failures for the same device
 the PM runtime will be reenabled due to disable_depth overflow).

To fix this problem, add devices to dpm_late_early_list regardless
of whether or not device_suspend_late() returns errors for them.

That will ensure failures in there to be handled consistently for
all devices regardless of their async suspend/resume status.

Reported-by: Grygorii Strashko <grygorii.strashko at ti.com>
Tested-by: Grygorii Strashko <grygorii.strashko at ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/base/power/main.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 30b7bbf..964d5e4 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1262,14 +1262,15 @@ int dpm_suspend_late(pm_message_t state)
 		error = device_suspend_late(dev);

 		mutex_lock(&dpm_list_mtx);
+		if (!list_empty(&dev->power.entry))
+			list_move(&dev->power.entry, &dpm_late_early_list);
+
 		if (error) {
 			pm_dev_err(dev, state, " late", error);
 			dpm_save_failed_dev(dev_name(dev));
 			put_device(dev);
 			break;
 		}
-		if (!list_empty(&dev->power.entry))
-			list_move(&dev->power.entry, &dpm_late_early_list);
 		put_device(dev);

 		if (async_error)
--
2.7.4