fix for msg4 scheduler in case vrb map for selected slot is occupied

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c

@@ -1425,10 +1425,12 @@ void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
       return;
     }
 
-    if(UE->enc_rval.encoded <= 0) return; // need to wait until RRCSetup is encoded
-
     NR_UE_sched_ctrl_t *sched_ctrl = &UE->UE_sched_ctrl;
 
+    uint16_t mac_sdu_length = mac_rrc_nr_data_req(module_idP, CC_id, frameP, CCCH, ra->rnti, 1, NULL);
+
+    if(mac_sdu_length <= 0) return; // need to wait until RRCSetup is encoded
+
     long BWPStart = 0;
     long BWPSize = 0;
     NR_Type0_PDCCH_CSS_config_t *type0_PDCCH_CSS_config = NULL;
@@ -1464,6 +1466,58 @@ void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
       return;
     }
 
+    // Checking if the DCI allocation is feasible in current subframe
+    nfapi_nr_dl_tti_request_body_t *dl_req = &nr_mac->DL_req[CC_id].dl_tti_request_body;
+    if (dl_req->nPDUs > NFAPI_NR_MAX_DL_TTI_PDUS - 2) {
+      LOG_I(NR_MAC, "[RAPROC] Subframe %d: FAPI DL structure is full, skip scheduling UE %d\n", slotP, ra->rnti);
+      return;
+    }
+
+    uint8_t time_domain_assignment = get_dl_tda(nr_mac, scc, slotP);
+    NR_tda_info_t msg4_tda = nr_get_pdsch_tda_info(dl_bwp, time_domain_assignment);
+    NR_pdsch_dmrs_t dmrs_info = get_dl_dmrs_params(scc,
+                                                   dl_bwp,
+                                                   &msg4_tda,
+                                                   1);
+
+    uint8_t mcsTableIdx = dl_bwp->mcsTableIdx;
+    uint8_t mcsIndex = 0;
+    int rbStart = 0;
+    int rbSize = 0;
+    uint8_t tb_scaling = 0;
+    uint32_t tb_size = 0;
+    uint8_t subheader_len = (mac_sdu_length < 256) ? sizeof(NR_MAC_SUBHEADER_SHORT) : sizeof(NR_MAC_SUBHEADER_LONG);
+    uint16_t pdu_length = mac_sdu_length + subheader_len + 7; //7 is contetion resolution length
+    uint16_t *vrb_map = cc[CC_id].vrb_map;
+    // increase PRBs until we get to BWPSize or TBS is bigger than MAC PDU size
+    do {
+      if(rbSize < BWPSize)
+        rbSize++;
+      else
+        mcsIndex++;
+      LOG_D(NR_MAC,"Calling nr_compute_tbs with N_PRB_DMRS %d, N_DMRS_SLOT %d\n",dmrs_info.N_PRB_DMRS,dmrs_info.N_DMRS_SLOT);
+      tb_size = nr_compute_tbs(nr_get_Qm_dl(mcsIndex, mcsTableIdx),
+                                     nr_get_code_rate_dl(mcsIndex, mcsTableIdx),
+                                     rbSize, msg4_tda.nrOfSymbols, dmrs_info.N_PRB_DMRS * dmrs_info.N_DMRS_SLOT, 0, tb_scaling,1) >> 3;
+    } while (tb_size < pdu_length && mcsIndex<=28);
+
+    AssertFatal(tb_size >= pdu_length,"Cannot allocate Msg4\n");
+
+    int i = 0;
+    while ((i < rbSize) && (rbStart + rbSize <= BWPSize)) {
+      if (vrb_map[BWPStart + rbStart + i]&SL_to_bitmap(msg4_tda.startSymbolIndex, msg4_tda.nrOfSymbols)) {
+        rbStart += i+1;
+        i = 0;
+      } else {
+        i++;
+      }
+    }
+
+    if (rbStart > (BWPSize - rbSize)) {
+      LOG_E(NR_MAC, "%s(): cannot find free vrb_map for RNTI %04x!\n", __func__, ra->rnti);
+      return;
+    }
+
     const int delta_PRI=0;
     int r_pucch = nr_get_pucch_resource(coreset, ra->UL_BWP.pucch_Config, CCEIndex);
 
@@ -1500,6 +1554,7 @@ void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
     NR_sched_pucch_t *pucch = &sched_ctrl->sched_pucch[alloc];
     harq->feedback_slot = pucch->ul_slot;
     harq->feedback_frame = pucch->frame;
+    harq->tb_size = tb_size;
 
     uint8_t *buf = (uint8_t *) harq->transportBlock;
     // Bytes to be transmitted
@@ -1533,56 +1588,6 @@ void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
       }
     }
 
-    uint8_t time_domain_assignment = get_dl_tda(nr_mac, scc, slotP);
-    NR_tda_info_t msg4_tda = nr_get_pdsch_tda_info(dl_bwp, time_domain_assignment);
-    NR_pdsch_dmrs_t dmrs_info = get_dl_dmrs_params(scc,
-                                                   dl_bwp,
-                                                   &msg4_tda,
-                                                   1);
-
-    uint8_t mcsTableIdx = dl_bwp->mcsTableIdx;
-    uint8_t mcsIndex = 0;
-    int rbStart = 0;
-    int rbSize = 0;
-    uint8_t tb_scaling = 0;
-    uint16_t *vrb_map = cc[CC_id].vrb_map;
-    // increase PRBs until we get to BWPSize or TBS is bigger than MAC PDU size
-    do {
-      if(rbSize < BWPSize)
-        rbSize++;
-      else
-        mcsIndex++;
-      LOG_D(NR_MAC,"Calling nr_compute_tbs with N_PRB_DMRS %d, N_DMRS_SLOT %d\n",dmrs_info.N_PRB_DMRS,dmrs_info.N_DMRS_SLOT);
-      harq->tb_size = nr_compute_tbs(nr_get_Qm_dl(mcsIndex, mcsTableIdx),
-                                     nr_get_code_rate_dl(mcsIndex, mcsTableIdx),
-                                     rbSize, msg4_tda.nrOfSymbols, dmrs_info.N_PRB_DMRS * dmrs_info.N_DMRS_SLOT, 0, tb_scaling,1) >> 3;
-    } while (harq->tb_size < ra->mac_pdu_length && mcsIndex<=28);
-
-    AssertFatal(harq->tb_size >= ra->mac_pdu_length,"Cannot allocate Msg4\n");
-
-    int i = 0;
-    while ((i < rbSize) && (rbStart + rbSize <= BWPSize)) {
-      if (vrb_map[BWPStart + rbStart + i]&SL_to_bitmap(msg4_tda.startSymbolIndex, msg4_tda.nrOfSymbols)) {
-        rbStart += i+1;
-        i = 0;
-      } else {
-        i++;
-      }
-    }
-
-    if (rbStart > (BWPSize - rbSize)) {
-      LOG_E(NR_MAC, "%s(): cannot find free vrb_map for RNTI %04x!\n", __func__, ra->rnti);
-      return;
-    }
-
-    // Checking if the DCI allocation is feasible in current subframe
-    nfapi_nr_dl_tti_request_body_t *dl_req = &nr_mac->DL_req[CC_id].dl_tti_request_body;
-    if (dl_req->nPDUs > NFAPI_NR_MAX_DL_TTI_PDUS - 2) {
-      LOG_I(NR_MAC, "[RAPROC] Subframe %d: FAPI DL structure is full, skip scheduling UE %d\n", slotP, ra->rnti);
-      return;
-    }
-
-
     // look up the PDCCH PDU for this CC, BWP, and CORESET. If it does not exist, create it. This is especially
     // important if we have multiple RAs, and the DLSCH has to reuse them, so we need to mark them
     const int coresetid = coreset->controlResourceSetId;

openair2/RRC/NR/L2_nr_interface.c

@@ -117,7 +117,8 @@ uint16_t mac_rrc_nr_data_req(const module_id_t Mod_idP,
                              const rb_id_t     Srb_id,
                              const rnti_t      rnti,
                              const uint8_t     Nb_tb,
-                             uint8_t *const    buffer_pP ){
+                             uint8_t *const    buffer_pP)
+{
 
 #ifdef DEBUG_RRC
   LOG_D(RRC,"[eNB %d] mac_rrc_data_req to SRB ID=%ld\n",Mod_idP,Srb_id);
@@ -162,19 +163,21 @@ uint16_t mac_rrc_nr_data_req(const module_id_t Mod_idP,
   if ((Srb_id & RAB_OFFSET) == CCCH) {
     LOG_D(NR_RRC,"[gNB %d] Frame %d CCCH request (Srb_id %ld)\n", Mod_idP, frameP, Srb_id);
 
-    char *payload_pP;
     struct rrc_gNB_ue_context_s *ue_context_p = rrc_gNB_get_ue_context(RC.nrrrc[Mod_idP], rnti);
 
     LOG_D(NR_RRC,"[gNB %d] Frame %d CCCH request (Srb_id %ld)\n", Mod_idP, frameP, Srb_id);
     if (ue_context_p == NULL) {
-      LOG_E(NR_RRC,"[gNB %d] Frame %d CCCH request but no ue_context\n", Mod_idP, frameP);
+      if(buffer_pP != NULL)
+        LOG_E(NR_RRC,"[gNB %d] Frame %d CCCH request but no ue_context\n", Mod_idP, frameP);
       return 0;
     }
 
     uint16_t payload_size = ue_context_p->ue_context.Srb0.Tx_buffer.payload_size;
+    if (buffer_pP == NULL)
+      return payload_size;
     // check if data is there for MAC
     if (payload_size > 0) {
-      payload_pP = ue_context_p->ue_context.Srb0.Tx_buffer.Payload;
+      char *payload_pP = ue_context_p->ue_context.Srb0.Tx_buffer.Payload;
       LOG_D(NR_RRC,"[gNB %d] CCCH has %d bytes (dest: %p, src %p)\n", Mod_idP, payload_size, buffer_pP, payload_pP);
       // Fill buffer
       memcpy((void *)buffer_pP, (void*)payload_pP, payload_size);