[PATCH] rtc class locking bugfixes
I got a lockdep warning when running "rtctest" so I though it'd be good
to see what was up.
- The warning was for rtc->irq_task_lock, gotten from rtc_update_irq()
by irq handlerss ... but in a handful of other cases, grabbed without
blocking IRQs.
- Some callers to rtc_update_irq() were not ensuring IRQs were blocked,
yet the routine expects that; make sure all callers block IRQs.
It would appear that RTC API tests haven't been part of anyone's kernel
regression test suite recently, at least not with lockdep running.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index 3109865..814b9e1 100644
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -61,7 +61,9 @@
int err;
err = rtc_read_time(&rtc->class_dev, &tm);
- spin_lock_irq(&rtc->irq_lock);
+
+ local_irq_disable();
+ spin_lock(&rtc->irq_lock);
if (rtc->stop_uie_polling || err) {
rtc->uie_task_active = 0;
} else if (rtc->oldsecs != tm.tm_sec) {
@@ -74,11 +76,11 @@
} else if (schedule_work(&rtc->uie_task) == 0) {
rtc->uie_task_active = 0;
}
- spin_unlock_irq(&rtc->irq_lock);
+ spin_unlock(&rtc->irq_lock);
if (num)
rtc_update_irq(&rtc->class_dev, num, RTC_UF | RTC_IRQF);
+ local_irq_enable();
}
-
static void rtc_uie_timer(unsigned long data)
{
struct rtc_device *rtc = (struct rtc_device *)data;
@@ -238,10 +240,10 @@
/* avoid conflicting IRQ users */
if (cmd == RTC_PIE_ON || cmd == RTC_PIE_OFF || cmd == RTC_IRQP_SET) {
- spin_lock(&rtc->irq_task_lock);
+ spin_lock_irq(&rtc->irq_task_lock);
if (rtc->irq_task)
err = -EBUSY;
- spin_unlock(&rtc->irq_task_lock);
+ spin_unlock_irq(&rtc->irq_task_lock);
if (err < 0)
return err;