[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>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-test.c b/drivers/rtc/rtc-test.c
index bc4bd24508a2..6ef9c62d5032 100644
--- a/drivers/rtc/rtc-test.c
+++ b/drivers/rtc/rtc-test.c
@@ -99,6 +99,7 @@ static ssize_t test_irq_store(struct device *dev,
         struct rtc_device *rtc = platform_get_drvdata(plat_dev);
 
         retval = count;
+        local_irq_disable();
         if (strncmp(buf, "tick", 4) == 0)
                 rtc_update_irq(&rtc->class_dev, 1, RTC_PF | RTC_IRQF);
         else if (strncmp(buf, "alarm", 5) == 0)
@@ -107,6 +108,7 @@ static ssize_t test_irq_store(struct device *dev,
                 rtc_update_irq(&rtc->class_dev, 1, RTC_UF | RTC_IRQF);
         else
                 retval = -EINVAL;
+        local_irq_enable();
 
         return retval;
 }