[PATCH 3.16 293/328] PM / core: Clear the direct_complete flag on errors

From: Ben Hutchings
Date: Sun Dec 09 2018 - 17:21:17 EST

3.16.62-rc1 review patch. If anyone has any objections, please let me know.


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

commit 69e445ab8b66a9f30519842ef18be555d3ee9b51 upstream.

If __device_suspend() runs asynchronously (in which case the device
passed to it is in dpm_suspended_list at that point) and it 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 that 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>
Tested-by: Al Cooper <alcooperx@xxxxxxxxx>
Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
drivers/base/power/main.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1336,8 +1336,10 @@ static int __device_suspend(struct devic

dpm_wait_for_children(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
@@ -1349,6 +1351,7 @@ 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;