rtc: make rtc_update_irq callable with irqs enabled

The rtc_update_irq() might be called with irqs enabled, if a interrupt
handler was registered without IRQF_DISABLED.  Use
spin_lock_irqsave/spin_unlock_irqrestore instead of spin_lock/spin_unlock.

Also update kerneldoc and drivers which do extra work to follow the
current interface spec, as suggestted by David Brownell.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 4348c4b0d45..4cdb31a362c 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -371,19 +371,21 @@ EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
  * @rtc: the rtc device
  * @num: how many irqs are being reported (usually one)
  * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
- * Context: in_interrupt(), irqs blocked
+ * Context: any
  */
 void rtc_update_irq(struct rtc_device *rtc,
                 unsigned long num, unsigned long events)
 {
-        spin_lock(&rtc->irq_lock);
+        unsigned long flags;
+
+        spin_lock_irqsave(&rtc->irq_lock, flags);
         rtc->irq_data = (rtc->irq_data + (num << 8)) | events;
-        spin_unlock(&rtc->irq_lock);
+        spin_unlock_irqrestore(&rtc->irq_lock, flags);
 
-        spin_lock(&rtc->irq_task_lock);
+        spin_lock_irqsave(&rtc->irq_task_lock, flags);
         if (rtc->irq_task)
                 rtc->irq_task->func(rtc->irq_task->private_data);
-        spin_unlock(&rtc->irq_task_lock);
+        spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
 
         wake_up_interruptible(&rtc->irq_queue);
         kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);