lwmac: add re-initialize radio support.

sys/include/net/gnrc/lwmac/lwmac.h

@@ -316,6 +316,19 @@ extern "C" {
 #endif
 /** @} */
 
+/**
+* @brief Maximum preamble attempts before re-initialize radio in LWMAC.
+*
+* After a long period of run time, a radio may be in wrong condition which needs to be
+* re-calibrated. This is indicated by having a series of continuous preamble failure (no WA)
+* in LWMAC. In case we have @ref CONFIG_GNRC_LWMAC_RADIO_REINIT_THRESHOLD number of preamble
+* failure, then we re-initialize the radio, trying to re-calibrate the radio for bringing it
+* back to normal condition.
+*/
+#ifndef CONFIG_GNRC_LWMAC_RADIO_REINIT_THRESHOLD
+#define CONFIG_GNRC_LWMAC_RADIO_REINIT_THRESHOLD     (10U)
+#endif
+
 /**
  * @brief   Creates an IEEE 802.15.4 LWMAC network interface
  *

sys/include/net/gnrc/mac/types.h

@@ -197,6 +197,7 @@ typedef struct {
     uint8_t bcast_seqnr;               /**< Sequence number for broadcast data to filter at receiver */
     uint8_t tx_burst_count;            /**< Count how many consecutive packets have been transmitted */
     uint8_t tx_retry_count;            /**< Count how many Tx-retrials have been executed before packet drop */
+    uint8_t preamble_fail_counts;      /**< Preamble trial failure count. */
 #endif
 
 #ifdef MODULE_GNRC_GOMACH

sys/net/gnrc/link_layer/lwmac/Kconfig

@@ -138,5 +138,16 @@ config GNRC_LWMAC_TIMEOUT_COUNT
     help
         Configure 'CONFIG_GNRC_LWMAC_TIMEOUT_COUNT', the default value for the
         maximum number of parallel timeouts in LWMAC.
+config GNRC_LWMAC_RADIO_REINIT_THRESHOLD
+    int "Maximum preamble attempts before re-initialize radio"
+    default 10
+    help
+        Configure 'CONFIG_GNRC_LWMAC_RADIO_REINIT_THRESHOLD', the maximum preamble
+        attempts before re-initialize radio. After a long period of run time, a radio
+        may be in wrong condition which needs to be re-calibrated. This is indicated
+        by having a series of continuous preamble failure (no WA) in LWMAC. In case
+        we have @ref GNRC_LWMAC_RADIO_REINI_THRESHOLD number of preamble failure,
+        then we re-initialize the radio, trying to re-calibrate the radio for bringing
+        it back to normal condition.
 
 endif # KCONFIG_MODULE_GNRC_LWMAC

sys/net/gnrc/link_layer/lwmac/lwmac.c

@@ -83,6 +83,38 @@ int gnrc_netif_lwmac_create(gnrc_netif_t *netif, char *stack, int stacksize,
                              &lwmac_ops);
 }
 
+static void lwmac_reinit_radio(gnrc_netif_t *netif)
+{
+    /* Initialize low-level driver. */
+    netif->dev->driver->init(netif->dev);
+
+    /* Set MAC address length. */
+    uint16_t src_len = netif->l2addr_len;
+    netif->dev->driver->set(netif->dev, NETOPT_SRC_LEN, &src_len, sizeof(src_len));
+
+    /* Set the MAC address of the device. */
+    if (netif->l2addr_len == IEEE802154_LONG_ADDRESS_LEN) {
+        netif->dev->driver->set(netif->dev,
+                                NETOPT_ADDRESS_LONG,
+                                netif->l2addr,
+                                sizeof(netif->l2addr));
+    }
+    else {
+        netif->dev->driver->set(netif->dev,
+                                NETOPT_ADDR_LEN,
+                                netif->l2addr,
+                                sizeof(netif->l2addr));
+    }
+
+   /* Enable RX-start and TX-started and TX-END interrupts. */
+   netopt_enable_t enable = NETOPT_ENABLE;
+   netif->dev->driver->set(netif->dev, NETOPT_RX_START_IRQ, &enable, sizeof(enable));
+   netif->dev->driver->set(netif->dev, NETOPT_RX_END_IRQ, &enable, sizeof(enable));
+   netif->dev->driver->set(netif->dev, NETOPT_TX_START_IRQ, &enable, sizeof(enable));
+   netif->dev->driver->set(netif->dev, NETOPT_TX_END_IRQ, &enable, sizeof(enable));
+
+}
+
 static gnrc_pktsnip_t *_make_netif_hdr(uint8_t *mhr)
 {
     gnrc_pktsnip_t *snip;
@@ -328,6 +360,7 @@ void lwmac_set_state(gnrc_netif_t *netif, gnrc_lwmac_state_t newstate)
         case GNRC_LWMAC_START: {
             rtt_handler(GNRC_LWMAC_EVENT_RTT_START, netif);
             lwmac_set_state(netif, GNRC_LWMAC_LISTENING);
+            netif->mac.tx.preamble_fail_counts = 0;
             break;
         }
         case GNRC_LWMAC_STOP: {
@@ -576,6 +609,13 @@ static void _tx_management(gnrc_netif_t *netif)
             gnrc_lwmac_set_tx_continue(netif, false);
             gnrc_lwmac_set_quit_tx(netif, true);
             /* TX packet will be dropped, no automatic resending here. */
+
+            /* Re-initialize the radio when needed. */
+            if (netif->mac.tx.preamble_fail_counts >= CONFIG_GNRC_LWMAC_RADIO_REINIT_THRESHOLD) {
+                netif->mac.tx.preamble_fail_counts = 0;
+                LOG_INFO("[LWMAC] Re-initialize radio.");
+                lwmac_reinit_radio(netif);
+            }
             /* Intentionally falls through */
 
         case GNRC_LWMAC_TX_STATE_SUCCESSFUL:

sys/net/gnrc/link_layer/lwmac/tx_state_machine.c

@@ -685,6 +685,7 @@ static bool _lwmac_tx_update(gnrc_netif_t *netif)
                 LOG_WARNING("WARNING: [LWMAC-tx] No response from destination\n");
                 netif->mac.tx.state = GNRC_LWMAC_TX_STATE_FAILED;
                 reschedule = true;
+                netif->mac.tx.preamble_fail_counts++;
                 break;
             }
 
@@ -735,6 +736,7 @@ static bool _lwmac_tx_update(gnrc_netif_t *netif)
             if (tx_info & GNRC_LWMAC_TX_SUCCESS) {
                 netif->mac.tx.state = GNRC_LWMAC_TX_STATE_SEND_DATA;
                 reschedule = true;
+                netif->mac.tx.preamble_fail_counts = 0;
                 break;
             }
             else {