rtc: don't return -EBUSY when mutex_lock_interruptible() fails

It was pointed out that the RTC framework handles its mutex locks oddly
...  returning -EBUSY when interrupted.  This fixes that by returning the
value of mutex_lock_interruptible() (i.e.  -EINTR).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/interface.c

@@ -20,7 +20,7 @@ int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
 
 	err = mutex_lock_interruptible(&rtc->ops_lock);
 	if (err)
-		return -EBUSY;
+		return err;
 
 	if (!rtc->ops)
 		err = -ENODEV;
@@ -46,7 +46,7 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
 
 	err = mutex_lock_interruptible(&rtc->ops_lock);
 	if (err)
-		return -EBUSY;
+		return err;
 
 	if (!rtc->ops)
 		err = -ENODEV;
@@ -66,7 +66,7 @@ int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
 
 	err = mutex_lock_interruptible(&rtc->ops_lock);
 	if (err)
-		return -EBUSY;
+		return err;
 
 	if (!rtc->ops)
 		err = -ENODEV;
@@ -106,7 +106,7 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *al
 
 	err = mutex_lock_interruptible(&rtc->ops_lock);
 	if (err)
-		return -EBUSY;
+		return err;
 
 	if (rtc->ops == NULL)
 		err = -ENODEV;
@@ -293,7 +293,7 @@ int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 
 	err = mutex_lock_interruptible(&rtc->ops_lock);
 	if (err)
-		return -EBUSY;
+		return err;
 
 	if (!rtc->ops)
 		err = -ENODEV;

drivers/rtc/rtc-dev.c

@@ -221,7 +221,7 @@ static long rtc_dev_ioctl(struct file *file,
 
 	err = mutex_lock_interruptible(&rtc->ops_lock);
 	if (err)
-		return -EBUSY;
+		return err;
 
 	/* check that the calling task has appropriate permissions
 	 * for certain ioctls. doing this check here is useful