pm selftest: rtc paranoia

Cope with a quirk of some RTCs (notably ACPI ones) which aren't guaranteed
to implement oneshot behavior when they woke the system from sleeep:
forcibly disable the alarm, just in case.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/kernel/power/main.c b/kernel/power/main.c
index 95bff23ecda..0b7476f5d2a 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -635,6 +635,13 @@ static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state)
         }
         if (status < 0)
                 printk(err_suspend, status);
+
+        /* Some platforms can't detect that the alarm triggered the
+         * wakeup, or (accordingly) disable it after it afterwards.
+         * It's supposed to give oneshot behavior; cope.
+         */
+        alm.enabled = false;
+        rtc_set_alarm(rtc, &alm);
 }
 
 static int __init has_wakealarm(struct device *dev, void *name_ptr)