SQUASHME: fix interrupt handling

RIOT-OS · May 7, 2015 · 268c737 · 268c737
1 parent 49a16d9
commit 268c737
Showing 1 changed file with 8 additions and 6 deletions.
diff --git a/cpu/samd21/periph/rtt.c b/cpu/samd21/periph/rtt.c
@@ -102,9 +102,10 @@ void rtt_set_overflow_cb(rtt_cb_t cb, void *arg)
     rtt_callback.overflow_cb = cb;
     rtt_callback.overflow_arg = arg;
 
-    /* Enable Overflow Interrupt */
+    /* Enable Overflow Interrupt and clear flag */
     RtcMode0 *rtcMode0 = &(RTT_DEV);
     rtcMode0->INTENSET.bit.OVF = 1;
+    rtcMode0->INTFLAG.bit.OVF = 1;
 }
 
 void rtt_clear_overflow_cb(void)
@@ -140,8 +141,9 @@ void rtt_set_alarm(uint32_t alarm, rtt_cb_t cb, void *arg)
     rtcMode0->COMP[0].reg = alarm;
     while (rtcMode0->STATUS.bit.SYNCBUSY);
 
-    /* Enable Compare Interrupt */
+    /* Enable Compare Interrupt and clear flag */
     rtcMode0->INTENSET.bit.CMP0 = 1;
+    rtcMode0->INTFLAG.bit.CMP0 = 1;
 }
 
 void rtt_clear_alarm(void)
@@ -179,14 +181,14 @@ void RTT_ISR(void)
     RtcMode0 *rtcMode0 = &(RTT_DEV);
     uint8_t status = rtcMode0->INTFLAG.reg;
 
-    if (status & RTC_MODE0_INTFLAG_CMP0) {
+    if ( (status & RTC_MODE0_INTFLAG_CMP0) && (rtt_callback.alarm_cb != NULL) ) {
         rtt_callback.alarm_cb(rtt_callback.alarm_cb);
-        rtcMode0->INTFLAG.reg = RTC_MODE0_INTFLAG_CMP0;
+        rtcMode0->INTFLAG.bit.CMP0 = 1;
     }
 
-    if (status & RTC_MODE0_INTFLAG_OVF) {
+    if ( (status & RTC_MODE0_INTFLAG_OVF) && (rtt_callback.overflow_cb != NULL) ) {
         rtt_callback.overflow_cb(rtt_callback.overflow_arg);
-        rtcMode0->INTFLAG.reg = RTC_MODE0_INTFLAG_OVF;
+        rtcMode0->INTFLAG.bit.OVF = 1;
     }
 
     if (sched_context_switch_request) {