[PATCH] PM / core: Clear the direct_complete flag on errors

From: Rafael J. Wysocki
Date: Thu Oct 04 2018 - 05:11:18 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

If __device_suspend() returns early on an error or pending wakeup
and the power.direct_complete flag has been set for the device
already, the subsequent device_resume() will be confused by it
and it will call pm_runtime_enable() incorrectly, as runtime PM
has not been disabled for the device by __device_suspend().

To avoid that, clear power.direct_complete if __device_suspend()
is not going to disable runtime PM for the device before returning.

Fixes: aae4518b3124 (PM / sleep: Mechanism to avoid resuming runtime-suspended devices unnecessarily)
Reported-by: Al Cooper <alcooperx@xxxxxxxxx>
Cc: 3.16+ <stable@xxxxxxxxxxxxxxx> # 3.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/base/power/main.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

Index: linux-pm/drivers/base/power/main.c
===================================================================
--- linux-pm.orig/drivers/base/power/main.c
+++ linux-pm/drivers/base/power/main.c
@@ -1713,8 +1713,10 @@ static int __device_suspend(struct devic

dpm_wait_for_subordinate(dev, async);

- if (async_error)
+ if (async_error) {
+ dev->power.direct_complete = false;
goto Complete;
+ }

/*
* If a device configured to wake up the system from sleep states
@@ -1726,6 +1728,7 @@ static int __device_suspend(struct devic
pm_wakeup_event(dev, 0);

if (pm_wakeup_pending()) {
+ dev->power.direct_complete = false;
async_error = -EBUSY;
goto Complete;
}