FHSS: Synchronization must be done in critical state

(cherry picked from commit 60c02049ae56d3381e750cd2d21ce26ca71789b4)

Author: Jarkko Paso

source/Service_Libs/fhss/fhss_mac_interface.c

@@ -22,6 +22,7 @@
 #include "Service_Libs/fhss/fhss.h"
 #include "Service_Libs/fhss/fhss_channel.h"
 #include "Service_Libs/fhss/fhss_beacon.h"
+#include "platform/arm_hal_interrupt.h"
 #include "randLIB.h"
 #include "ns_trace.h"
 
@@ -124,10 +125,12 @@ void fhss_receive_frame_cb(const fhss_api_t *api, uint16_t pan_id, uint8_t *sour
             if (!fhss_compare_with_synch_parent_address(fhss_structure, source_address)) {
                 // Synch parent address needs to be updated in case parent has changed
                 fhss_update_synch_parent_address(fhss_structure);
+                platform_enter_critical();
                 // Calculate time since the Beacon was received
                 uint32_t elapsed_time = api->read_timestamp(api) - timestamp;
                 // Synchronize to given PAN
                 fhss_beacon_received(fhss_structure, synch_info, elapsed_time);
+                platform_exit_critical();
             }
         }
     } else if (FHSS_SYNCH_REQUEST_FRAME == frame_type) {
@@ -220,10 +223,12 @@ void fhss_synch_state_set_cb(const fhss_api_t *api, fhss_states fhss_state, uint
         fhss_beacon_info_t *beacon_info = fhss_get_beacon_info(fhss_structure, pan_id);
         if (beacon_info) {
             memcpy(fhss_structure->synch_parent, beacon_info->source_address, 8);
+            platform_enter_critical();
             // Calculate time since the Beacon was received
             uint32_t elapsed_time = api->read_timestamp(api) - beacon_info->timestamp;
             // Synchronize to given PAN
             fhss_beacon_received(fhss_structure, beacon_info->synch_info, elapsed_time);
+            platform_exit_critical();
             // Delete stored Beacon infos
             fhss_flush_beacon_info_storage(fhss_structure);
             fhss_structure->synch_panid = pan_id;