PM: Fix async resume following suspend failure
The PM core doesn't handle suspend failures correctly when it comes to
asynchronously suspended devices. These devices are moved onto the
dpm_suspended_list as soon as the corresponding async thread is
started up, and they remain on the list even if they fail to suspend
or the sleep transition is cancelled before they get suspended. As a
result, when the PM core unwinds the transition, it tries to resume
the devices even though they were never suspended.
This patch (as1474) fixes the problem by adding a new "is_suspended"
flag to dev_pm_info. Devices are resumed only if the flag is set.
[rjw:
* Moved the dev->power.is_suspended check into device_resume(),
because we need to complete dev->power.completion and clear
dev->power.is_prepared too for devices whose
dev->power.is_suspended flags are unset.
* Fixed __device_suspend() to avoid setting dev->power.is_suspended
if async_error is different from zero.]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@kernel.org
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index bf5a59a..06f09bf 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -58,6 +58,7 @@
void device_pm_init(struct device *dev)
{
dev->power.is_prepared = false;
+ dev->power.is_suspended = false;
init_completion(&dev->power.completion);
complete_all(&dev->power.completion);
dev->power.wakeup = NULL;
@@ -517,6 +518,9 @@
*/
dev->power.is_prepared = false;
+ if (!dev->power.is_suspended)
+ goto Unlock;
+
if (dev->pwr_domain) {
pm_dev_dbg(dev, state, "power domain ");
error = pm_op(dev, &dev->pwr_domain->ops, state);
@@ -552,6 +556,9 @@
}
End:
+ dev->power.is_suspended = false;
+
+ Unlock:
device_unlock(dev);
complete_all(&dev->power.completion);
@@ -839,11 +846,11 @@
device_lock(dev);
if (async_error)
- goto End;
+ goto Unlock;
if (pm_wakeup_pending()) {
async_error = -EBUSY;
- goto End;
+ goto Unlock;
}
if (dev->pwr_domain) {
@@ -881,6 +888,9 @@
}
End:
+ dev->power.is_suspended = !error;
+
+ Unlock:
device_unlock(dev);
complete_all(&dev->power.completion);