Fix polling behaviour on Thread Stop. (#1403)

* Fix polling behaviour on Thread Stop.

src/core/thread/mesh_forwarder.cpp

@@ -841,6 +841,16 @@ exit:
     return error;
 }
 
+void MeshForwarder::SetRxOff()
+{
+    mNetif.GetMac().SetRxOnWhenIdle(false);
+
+    if (mPollTimer.IsRunning())
+    {
+        mPollTimer.Stop();
+    }
+}
+
 bool MeshForwarder::GetRxOnWhenIdle()
 {
     return mNetif.GetMac().GetRxOnWhenIdle();
@@ -852,11 +862,14 @@ void MeshForwarder::SetRxOnWhenIdle(bool aRxOnWhenIdle)
 
     if (aRxOnWhenIdle)
     {
-        mPollTimer.Stop();
+        if (mPollTimer.IsRunning())
+        {
+            mPollTimer.Stop();
+        }
     }
     else
     {
-        mPollTimer.Start(mPollPeriod);
+        ScheduleNextPoll(mPollPeriod);
     }
 }
 
@@ -888,7 +901,10 @@ void MeshForwarder::SetPollPeriod(uint32_t aPeriod)
             mPollPeriod = aPeriod;
         }
 
-        mPollTimer.Start(mPollPeriod);
+        if (mPollTimer.IsRunning() && ((mNetif.GetMle().GetDeviceMode() & Mle::ModeTlv::kModeFFD) == 0))
+        {
+            ScheduleNextPoll(mPollPeriod);
+        }
     }
 }
 
@@ -897,6 +913,18 @@ uint32_t MeshForwarder::GetPollPeriod()
     return mPollPeriod;
 }
 
+void MeshForwarder::ScheduleNextPoll(uint32_t aDelay)
+{
+    if (aDelay)
+    {
+        mPollTimer.Start(aDelay);
+    }
+    else
+    {
+        otLogWarnMac("Cannot start poll timer with uninitialized value of poll period.");
+    }
+}
+
 void MeshForwarder::HandlePollTimer(void *aContext)
 {
     static_cast<MeshForwarder *>(aContext)->HandlePollTimer();
@@ -922,7 +950,7 @@ void MeshForwarder::HandlePollTimer()
     case kThreadError_NoBufs:
         // Failed to send DataRequest due to a lack of buffers.
         // Try again following a brief pause to free buffers.
-        mPollTimer.Start(kDataRequestRetryDelay);
+        ScheduleNextPoll(kDataRequestRetryDelay);
         break;
 
     case kThreadError_Already:
@@ -935,7 +963,7 @@ void MeshForwarder::HandlePollTimer()
     // Intentional fall-thru
     default:
         // Restart for any other error which might originate from SendMessage().
-        mPollTimer.Start(mPollPeriod);
+        ScheduleNextPoll(mPollPeriod);
         break;
     }
 }
@@ -965,7 +993,7 @@ ThreadError MeshForwarder::SendMacDataRequest(void)
         otLogDebgMac("Sent poll");
 
         // restart the polling timer
-        mPollTimer.Start(mPollPeriod);
+        ScheduleNextPoll(mPollPeriod);
     }
     else
     {

src/core/thread/mesh_forwarder.hpp

@@ -113,6 +113,12 @@ public:
      */
     void HandleResolved(const Ip6::Address &aEid, ThreadError aError);
 
+    /**
+     * This method sets the radio receiver and polling timer off.
+     *
+     */
+    void SetRxOff(void);
+
     /**
      * This method indicates whether or not rx-on-when-idle mode is enabled.
      *
@@ -229,6 +235,8 @@ private:
 
     ThreadError CheckReachability(uint8_t *aFrame, uint8_t aFrameLength,
                                   const Mac::Address &aMeshSource, const Mac::Address &aMeshDest);
+
+    void ScheduleNextPoll(uint32_t aDelay);
     ThreadError GetMacDestinationAddress(const Ip6::Address &aIp6Addr, Mac::Address &aMacAddr);
     ThreadError GetMacSourceAddress(const Ip6::Address &aIp6Addr, Mac::Address &aMacAddr);
     Message *GetDirectTransmission(void);

src/core/thread/mle.cpp

@@ -508,7 +508,7 @@ ThreadError Mle::SetStateDetached(void)
     mDeviceState = kDeviceStateDetached;
     mParentRequestState = kParentIdle;
     mParentRequestTimer.Stop();
-    mNetif.GetMeshForwarder().SetRxOnWhenIdle(false);
+    mNetif.GetMeshForwarder().SetRxOff();
     mNetif.GetMle().HandleDetachStart();
     mNetif.GetIp6().SetForwardingEnabled(false);
     mNetif.GetIp6().mMpl.SetTimerExpirations(0);