[3.16.y-ckt extended stable] Patch "PM / Sleep: fix async suspend_late/freeze_late error handling" has been added to staging queue

[Luis Henriques]

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

    PM / Sleep: fix async suspend_late/freeze_late error handling

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt1.

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

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 16432a2822ee5673f2a6a187c7c30685ac12f912 Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak at intel.com>
Date: Fri, 24 Oct 2014 20:29:09 +0300
Subject: PM / Sleep: fix async suspend_late/freeze_late error handling

commit 246ef766743618a7cab059d6c4993270075b173e upstream.

If an asynchronous suspend_late or freeze_late callback fails
during the SUSPEND, FREEZE or QUIESCE phases, we don't propagate the
corresponding error correctly, in effect ignoring the error and
continuing the suspend-to-ram/hibernation. During suspend-to-ram this
could leave some devices without a valid saved context, leading to a
failure to reinitialize them during resume. During hibernation this
could leave some devices active interfeering with the creation /
restoration of the hibernation image. Also this could leave the
corresponding devices without a valid saved context and failure to
reinitialize them during resume.

Fixes: de377b397272 (PM / sleep: Asynchronous threads for suspend_late)
Signed-off-by: Imre Deak <imre.deak at intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/base/power/main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index bf412961a934..1f6da3ad6db0 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1262,6 +1262,8 @@ static int dpm_suspend_late(pm_message_t state)
 	}
 	mutex_unlock(&dpm_list_mtx);
 	async_synchronize_full();
+	if (!error)
+		error = async_error;
 	if (error) {
 		suspend_stats.failed_suspend_late++;
 		dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
--
2.1.0