PM / wakeup: Rework wakeup source timer cancellation
commit 1fad17fb1bbcd73159c2b992668a6957ecc5af8a upstream.
If wakeup_source_add() is called right after wakeup_source_remove()
for the same wakeup source, timer_setup() may be called for a
potentially scheduled timer which is incorrect.
To avoid that, move the wakeup source timer cancellation from
wakeup_source_drop() to wakeup_source_remove().
Moreover, make wakeup_source_remove() clear the timer function after
canceling the timer to let wakeup_source_not_registered() treat
unregistered wakeup sources in the same way as the ones that have
never been registered.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.4+ <stable@vger.kernel.org> # 4.4+
[ rjw: Subject, changelog, merged two patches together ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index f98121f1..9f51a16 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -113,7 +113,6 @@
if (!ws)
return;
- del_timer_sync(&ws->timer);
__pm_relax(ws);
}
EXPORT_SYMBOL_GPL(wakeup_source_drop);
@@ -201,6 +200,13 @@
list_del_rcu(&ws->entry);
spin_unlock_irqrestore(&events_lock, flags);
synchronize_srcu(&wakeup_srcu);
+
+ del_timer_sync(&ws->timer);
+ /*
+ * Clear timer.function to make wakeup_source_not_registered() treat
+ * this wakeup source as not registered.
+ */
+ ws->timer.function = NULL;
}
EXPORT_SYMBOL_GPL(wakeup_source_remove);