Fix #419: invalid DRs caused by TxParamSetupReq

Author: terrillmoore

src/lmic/lmic.c

@@ -577,6 +577,9 @@ static void resetJoinParams(void) {
     LMIC.rx1DrOffset = 0;
     LMIC.dn2Dr       = DR_DNW2;
     LMIC.dn2Freq     = FREQ_DNW2;
+#if LMIC_ENABLE_TxParamSetupReq
+    LMIC.txParam     = 0xFF;
+#endif
 }
 
 static void stateJustJoined (void) {
@@ -2676,14 +2679,14 @@ void LMIC_reset (void) {
     LMIC.opmode       =  OP_NONE;
     LMIC.errcr        =  CR_4_5;
     LMIC.adrEnabled   =  FCT_ADREN;
-    LMIC.dn2Dr        =  DR_DNW2;   // we need this for 2nd DN window of join accept
-    LMIC.dn2Freq      =  FREQ_DNW2; // ditto
+    resetJoinParams();
     LMIC.rxDelay      =  DELAY_DNW1;
 #if !defined(DISABLE_PING)
     LMIC.ping.freq    =  FREQ_PING; // defaults for ping
     LMIC.ping.dr      =  DR_PING;   // ditto
     LMIC.ping.intvExp =  0xFF;
 #endif // !DISABLE_PING
+
     LMICbandplan_resetDefaultChannels();
     DO_DEVDB(LMIC.devaddr,      devaddr);
     DO_DEVDB(LMIC.devNonce,     devNonce);

src/lmic/lmic_as923.c

@@ -76,16 +76,18 @@ static CONST_TABLE(u1_t, maxFrameLens_dwell1)[] = {
 
 static uint8_t
 LMICas923_getUplinkDwellBit(uint8_t mcmd_txparam) {
-        LMIC_API_PARAMETER(mcmd_txparam);
+        if (mcmd_txparam == 0xFF)
+                return 0;
 
-        return (LMIC.txParam & MCMD_TxParam_TxDWELL_MASK) != 0;
+        return (mcmd_txparam & MCMD_TxParam_TxDWELL_MASK) != 0;
 }
 
 static uint8_t
 LMICas923_getDownlinkDwellBit(uint8_t mcmd_txparam) {
-        LMIC_API_PARAMETER(mcmd_txparam);
+        if (mcmd_txparam == 0xFF)
+                return 0;
 
-        return (LMIC.txParam & MCMD_TxParam_RxDWELL_MASK) != 0;
+        return (mcmd_txparam & MCMD_TxParam_RxDWELL_MASK) != 0;
 }
 
 uint8_t LMICas923_maxFrameLen(uint8_t dr) {
@@ -118,6 +120,7 @@ static CONST_TABLE(s1_t, TXMAXEIRP)[16] = {
 };
 
 static int8_t LMICas923_getMaxEIRP(uint8_t mcmd_txparam) {
+        // if uninitialized, return default.
 	if (mcmd_txparam == 0xFF)
 		return AS923_TX_EIRP_MAX_DBM;
 	else
@@ -368,7 +371,7 @@ LMICas923_txDoneFSK(ostime_t delay, osjobcb_t func) {
 
 void
 LMICas923_initJoinLoop(void) {
-	LMIC.txParam = 0xFF;
+        // LMIC.txParam is set to 0xFF by the central code at init time.
         LMICeulike_initJoinLoop(NUM_DEFAULT_CHANNELS, /* adr dBm */ AS923_TX_EIRP_MAX_DBM);
 }
 

src/lmic/lmic_au921.c

@@ -65,6 +65,10 @@ static CONST_TABLE(u1_t, maxFrameLens_dwell1)[] = {
 
 static bit_t
 LMICau921_getUplinkDwellBit() {
+        // if uninitialized, return default.
+        if (LMIC.txParam == 0xFF) {
+                return 0;
+        }
         return (LMIC.txParam & MCMD_TxParam_TxDWELL_MASK) != 0;
 }
 
@@ -82,11 +86,29 @@ uint8_t LMICau921_maxFrameLen(uint8_t dr) {
         }
 }
 
+// from LoRaWAN 5.8: mapping from txParam to MaxEIRP
+static CONST_TABLE(s1_t, TXMAXEIRP)[16] = {
+	8, 10, 12, 13, 14, 16, 18, 20, 21, 24, 26, 27, 29, 30, 33, 36
+};
+
+static int8_t LMICau921_getMaxEIRP(uint8_t mcmd_txparam) {
+        // if uninitialized, return default.
+	if (mcmd_txparam == 0xFF)
+		return AU921_TX_EIRP_MAX_DBM;
+	else
+		return TABLE_GET_S1(
+			TXMAXEIRP,
+			(mcmd_txparam & MCMD_TxParam_MaxEIRP_MASK) >>
+				MCMD_TxParam_MaxEIRP_SHIFT
+			);
+}
+
 int8_t LMICau921_pow2dbm(uint8_t mcmd_ladr_p1) {
         if ((mcmd_ladr_p1 & MCMD_LinkADRReq_POW_MASK) == MCMD_LinkADRReq_POW_MASK)
                 return -128;
-        else
-                return ((s1_t)(30 - (((mcmd_ladr_p1)&MCMD_LinkADRReq_POW_MASK)<<1)));
+        else    {
+                return ((s1_t)(LMICau921_getMaxEIRP(LMIC.txParam) - (((mcmd_ladr_p1)&MCMD_LinkADRReq_POW_MASK)<<1)));
+        }
 }
 
 static CONST_TABLE(ostime_t, DR2HSYM_osticks)[] = {
@@ -209,7 +231,7 @@ bit_t LMIC_selectSubBand(u1_t band) {
 
 void LMICau921_updateTx(ostime_t txbeg) {
         u1_t chnl = LMIC.txChnl;
-        LMIC.txpow = AU921_TX_EIRP_MAX_DBM;
+        LMIC.txpow = LMICau921_getMaxEIRP(LMIC.txParam);
         if (chnl < 64) {
                 LMIC.freq = AU921_125kHz_UPFBASE + chnl*AU921_125kHz_UPFSTEP;
         } else {
@@ -252,10 +274,11 @@ void LMICau921_setRx1Params(void) {
 }
 
 void LMICau921_initJoinLoop(void) {
+        // LMIC.txParam is set to 0xFF by the central code at init time.
         LMICuslike_initJoinLoop();
 
         // initialize the adrTxPower.
-        LMIC.adrTxPow = 30; // dBm
+        LMIC.adrTxPow = LMICau921_getMaxEIRP(LMIC.txParam); // dBm
 
 }
 

src/lmic/lmic_eu_like.c

@@ -107,6 +107,14 @@ bit_t LMICeulike_mapChannels(u1_t chpage, u2_t chmap) {
 }
 
 bit_t LMICeulike_isDataRateFeasible(dr_t dr) {
+    // if the region uses TxpParam, then someone
+    // could have changed TxDwell, which makes some
+    // otherwise-legal DRs infeasible.
+#if LMIC_ENABLE_TxParamSetupReq
+    if (LMICbandplan_maxFrameLen(dr) == 0) {
+        return 0;
+    }
+#endif
         for (u1_t chnl = 0; chnl < MAX_CHANNELS; ++chnl) {
                 if ((LMIC.channelMap & (1 << chnl)) != 0 &&  // channel enabled
                         (LMIC.channelDrMap[chnl] & (1 << dr)) != 0)