2 files changed, 7 insertions, 0 deletions

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index dc87eda65814..eb415bd76494 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -458,6 +458,11 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
         if (rtc->uie_rtctimer.enabled == enabled)
                 goto out;
 
+        if (rtc->uie_unsupported) {
+                err = -EINVAL;
+                goto out;
+        }
+
         if (enabled) {
                 struct rtc_time tm;
                 ktime_t now, onesec;
diff --git a/drivers/rtc/rtc-mpc5121.c b/drivers/rtc/rtc-mpc5121.c
index 9d3caccfc250..613447abdbe5 100644
--- a/drivers/rtc/rtc-mpc5121.c
+++ b/drivers/rtc/rtc-mpc5121.c
@@ -360,6 +360,8 @@ static int __devinit mpc5121_rtc_probe(struct platform_device *op)
                                                 &mpc5200_rtc_ops, THIS_MODULE);
         }
 
+        rtc->rtc->uie_unsupported = 1;
+
         if (IS_ERR(rtc->rtc)) {
                 err = PTR_ERR(rtc->rtc);
                 goto out_free_irq;