Do generation of UL padding in nr_ue_get_sdu only

- removed code from outside this function
- generate random padding in RFSIM mode
- generate 0 padding in real-time
- padding is generated either to complete the PDU or to transmit a new one
  when no data from RLC was fetched

openair2/LAYER2/NR_MAC_UE/nr_ue_scheduler.c

@@ -1003,7 +1003,6 @@ NR_UE_L2_STATE_t nr_ue_scheduler(nr_downlink_indication_t *dl_info, nr_uplink_in
       LOG_D(NR_MAC, "In %s:[%d.%d]: number of UL PDUs: %d with UL transmission in [%d.%d]\n", __FUNCTION__, frame_tx, slot_tx, ul_config->number_pdus, ul_config->sfn, ul_config->slot);
 
       uint8_t ulsch_input_buffer[MAX_ULSCH_PAYLOAD_BYTES];
-      uint8_t data_existing = 0;
       nr_scheduled_response_t scheduled_response;
       fapi_nr_tx_request_t tx_req;
 
@@ -1035,45 +1034,15 @@ NR_UE_L2_STATE_t nr_ue_scheduler(nr_downlink_indication_t *dl_info, nr_uplink_in
                     mac->first_ul_tx[ulcfg_pdu->pusch_config_pdu.pusch_data.harq_process_id]==1)){
 
               // Getting IP traffic to be transmitted
-              data_existing = nr_ue_get_sdu(mod_id,
-                                            frame_tx,
-                                            slot_tx,
-                                            gNB_index,
-                                            ulsch_input_buffer,
-                                            TBS_bytes);
+              nr_ue_get_sdu(mod_id, frame_tx, slot_tx, gNB_index, ulsch_input_buffer, TBS_bytes);
             }
 
             LOG_D(NR_MAC,"Flipping NDI for harq_id %d\n",ulcfg_pdu->pusch_config_pdu.pusch_data.new_data_indicator);
             mac->UL_ndi[ulcfg_pdu->pusch_config_pdu.pusch_data.harq_process_id] = ulcfg_pdu->pusch_config_pdu.pusch_data.new_data_indicator;
             mac->first_ul_tx[ulcfg_pdu->pusch_config_pdu.pusch_data.harq_process_id] = 0;
 
-            // TBR use the proper function !
-            //Random traffic to be transmitted if there is no IP traffic available for this Tx opportunity
-            if (!data_existing) {
-              //Use zeros for the header bytes in noS1 mode, in order to make sure that the LCID is not valid
-              //and block this traffic from being forwarded to the upper layers at the gNB
-              LOG_D(PHY, "In %s: Random data to be transmitted: TBS_bytes %d \n", __FUNCTION__, TBS_bytes);
-
-              //Give the first byte a dummy value (a value not corresponding to any valid LCID based on 38.321, Table 6.2.1-2)
-              //in order to distinguish the PHY random packets at the MAC layer of the gNB receiver from the normal packets that should
-              //have a valid LCID (nr_process_mac_pdu function)
-              ulsch_input_buffer[0] = UL_SCH_LCID_PADDING;
-
-              for (int i = 1; i < TBS_bytes; i++) {
-                ulsch_input_buffer[i] = (unsigned char) rand();
-              }
-            }
           }
 
-          #ifdef DEBUG_MAC_PDU
-          LOG_D(PHY, "Is data existing ?: %d \n", data_existing);
-          LOG_I(PHY, "Printing MAC PDU to be encoded, TBS is: %d \n", TBS_bytes);
-          for (i = 0; i < TBS_bytes; i++) {
-            printf("%02x", ulsch_input_buffer[i]);
-          }
-          printf("\n");
-          #endif
-
           // Config UL TX PDU
           tx_req.slot = slot_tx;
           tx_req.sfn = frame_tx;
@@ -2084,8 +2053,6 @@ uint8_t nr_ue_get_sdu(module_id_t module_idP,
     }
   }
 
-  if (num_sdus > 0) {
-
   if (tot_mac_ce_len > 0) {
 
     LOG_D(NR_MAC, "In %s copying %d bytes of MAC CEs to the UL PDU \n", __FUNCTION__, tot_mac_ce_len);
@@ -2114,8 +2081,12 @@ uint8_t nr_ue_get_sdu(module_id_t module_idP,
     pdu++;
     buflen_remain--;
 
+    if (IS_SOFTMODEM_RFSIM) {
       for (int j = 0; j < buflen_remain; j++) {
-        pdu[j] = 0;
+        pdu[j] = (unsigned char) rand();
+      }
+    } else {
+      memset(pdu, 0, buflen_remain);
     }
 
     #ifdef ENABLE_MAC_PAYLOAD_DEBUG
@@ -2130,8 +2101,6 @@ uint8_t nr_ue_get_sdu(module_id_t module_idP,
   log_dump(NR_MAC, ulsch_buffer, buflen, LOG_DUMP_CHAR, "\n");
   #endif
 
-  }
-
   return num_sdus > 0 ? 1 : 0;
 
 }