[PATCH 3/4] clockevents: add device to clockevent_devices list if notify ADD success

From: Xiaotian Feng
Date: Thu Dec 10 2009 - 08:08:20 EST


When we register new clock_event_device, CLOCK_EVT_NOTIFY_ADD was notified,
but tick_check_new_device may fail to use new device, we should only add
device to clockevent_devices list when tick_check_new_device success.

Signed-off-by: Xiaotian Feng <dfeng@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Magnus Damm <damm@xxxxxxxxxx>
Cc: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
---
kernel/time/clockevents.c | 20 ++++++++++++++------
1 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 980c2c0..69d6c58 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -164,11 +164,14 @@ static int clockevents_do_notify(unsigned long reason, void *dev)
static void clockevents_notify_released(void)
{
struct clock_event_device *dev, *tmp;
+ int ret;

list_for_each_entry_safe(dev, tmp, &clockevents_released, list) {
- list_del(&dev->list);
- list_add(&dev->list, &clockevent_devices);
- clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev);
+ ret = clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev);
+ if (ret == NOTIFY_STOP) {
+ list_del(&dev->list);
+ list_add(&dev->list, &clockevent_devices);
+ }
}
}

@@ -179,15 +182,19 @@ static void clockevents_notify_released(void)
void clockevents_register_device(struct clock_event_device *dev)
{
unsigned long flags;
+ int ret;

BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
BUG_ON(!dev->cpumask);

spin_lock_irqsave(&clockevents_lock, flags);

- list_add(&dev->list, &clockevent_devices);
- clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev);
- clockevents_notify_released();
+ ret = clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev);
+ if (ret == NOTIFY_STOP) {
+ list_add(&dev->list, &clockevent_devices);
+ clockevents_notify_released();
+ } else
+ list_add(&dev->list, &clockevents_released);

spin_unlock_irqrestore(&clockevents_lock, flags);
}
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