clockevents: make device shutdown robust
The device shut down does not cleanup the next_event variable of the
clock event device. So when the device is reactivated the possible
stale next_event value can prevent the device to be reprogrammed as it
claims to wait on a event already.
This is the root cause of the resurfacing suspend/resume problem,
where systems need key press to come back to life.
Fix this by setting next_event to KTIME_MAX when the device is shut
down. Use a separate function for shutdown which takes care of that
and only keep the direct set mode call in the broadcast code, where we
can not touch the next_event value.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 1876b52..f8d9680 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -72,6 +72,16 @@
}
/**
+ * clockevents_shutdown - shutdown the device and clear next_event
+ * @dev: device to shutdown
+ */
+void clockevents_shutdown(struct clock_event_device *dev)
+{
+ clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN);
+ dev->next_event.tv64 = KTIME_MAX;
+}
+
+/**
* clockevents_program_event - Reprogram the clock event device.
* @expires: absolute expiry time (monotonic clock)
*
@@ -206,7 +216,7 @@
if (new) {
BUG_ON(new->mode != CLOCK_EVT_MODE_UNUSED);
- clockevents_set_mode(new, CLOCK_EVT_MODE_SHUTDOWN);
+ clockevents_shutdown(new);
}
local_irq_restore(flags);
}
