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authorBrian Norris <briannorris@chromium.org>2016-11-09 17:21:08 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-11-26 09:56:57 +0100
commit4cba876de64d448b458dd271f49c0e6a80a639ce (patch)
tree62e223e35f410674e95133b6bd259728a6d6eda9
parent2e2c8f0e7502fe8a8b6879af6bc8957b949bf1af (diff)
PM / sleep: don't suspend parent when async child suspend_{noirq, late} fails
commit 6f75c3fd56daf547d684127a7f83c283c3c160d1 upstream. Consider two devices, A and B, where B is a child of A, and B utilizes asynchronous suspend (it does not matter whether A is sync or async). If B fails to suspend_noirq() or suspend_late(), or is interrupted by a wakeup (pm_wakeup_pending()), then it aborts and sets the async_error variable. However, device A does not (immediately) check the async_error variable; it may continue to run its own suspend_noirq()/suspend_late() callback. This is bad. We can resolve this problem by doing our error and wakeup checking (particularly, for the async_error flag) after waiting for children to suspend, instead of before. This also helps align the logic for the noirq and late suspend cases with the logic in __device_suspend(). It's easy to observe this erroneous behavior by, for example, forcing a device to sleep a bit in its suspend_noirq() (to ensure the parent is waiting for the child to complete), then return an error, and watch the parent suspend_noirq() still get called. (Or similarly, fake a wakeup event at the right (or is it wrong?) time.) Fixes: de377b397272 (PM / sleep: Asynchronous threads for suspend_late) Fixes: 28b6fd6e3779 (PM / sleep: Asynchronous threads for suspend_noirq) Reported-by: Jeffy Chen <jeffy.chen@rock-chips.com> Signed-off-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/base/power/main.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index e44944f4be77..2932a5bd892f 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1027,6 +1027,8 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a
TRACE_DEVICE(dev);
TRACE_SUSPEND(0);
+ dpm_wait_for_children(dev, async);
+
if (async_error)
goto Complete;
@@ -1038,8 +1040,6 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a
if (dev->power.syscore || dev->power.direct_complete)
goto Complete;
- dpm_wait_for_children(dev, async);
-
if (dev->pm_domain) {
info = "noirq power domain ";
callback = pm_noirq_op(&dev->pm_domain->ops, state);
@@ -1174,6 +1174,8 @@ static int __device_suspend_late(struct device *dev, pm_message_t state, bool as
__pm_runtime_disable(dev, false);
+ dpm_wait_for_children(dev, async);
+
if (async_error)
goto Complete;
@@ -1185,8 +1187,6 @@ static int __device_suspend_late(struct device *dev, pm_message_t state, bool as
if (dev->power.syscore || dev->power.direct_complete)
goto Complete;
- dpm_wait_for_children(dev, async);
-
if (dev->pm_domain) {
info = "late power domain ";
callback = pm_late_early_op(&dev->pm_domain->ops, state);