FeedbackDisabled is sent in RRCSetup, the UE doesn't have it during MSG4...

FeedbackDisabled is sent in RRCSetup, the UE doesn't have it during MSG4 reception, it can't be used

the standard in 213 8.4 says: "In response to the PDSCH reception with the UE contention resolution identity, the UE transmits HARQ-ACK information in a PUCCH."

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c

@@ -2148,6 +2148,16 @@ static void nr_generate_Msg4_MsgB(module_id_t module_idP,
       return;
     }
 
+    const int delta_PRI = 0;
+    int r_pucch = nr_get_pucch_resource(coreset, ra->UL_BWP.pucch_Config, CCEIndex);
+    LOG_D(NR_MAC, "Msg4 r_pucch %d (CCEIndex %d, delta_PRI %d)\n", r_pucch, CCEIndex, delta_PRI);
+    int alloc = nr_acknack_scheduling(nr_mac, UE, frameP, slotP, ra->beam_id, r_pucch, 1);
+    if (alloc < 0) {
+      LOG_D(NR_MAC,"Couldn't find a pucch allocation for ack nack (msg4) in frame %d slot %d\n", frameP, slotP);
+      reset_beam_status(&nr_mac->beam_info, frameP, slotP, ra->beam_id, n_slots_frame, beam.new_beam);
+      return;
+    }
+
     // HARQ management
     if (current_harq_pid < 0) {
       AssertFatal(sched_ctrl->available_dl_harq.head >= 0,
@@ -2156,39 +2166,16 @@ static void nr_generate_Msg4_MsgB(module_id_t module_idP,
       remove_front_nr_list(&sched_ctrl->available_dl_harq);
     }
 
-    const int delta_PRI = 0;
-
-    int alloc = -1;
-    if (!get_FeedbackDisabled(UE->sc_info.downlinkHARQ_FeedbackDisabled_r17, current_harq_pid)) {
-      int r_pucch = nr_get_pucch_resource(coreset, ra->UL_BWP.pucch_Config, CCEIndex);
-
-      LOG_D(NR_MAC, "Msg4 r_pucch %d (CCEIndex %d, delta_PRI %d)\n", r_pucch, CCEIndex, delta_PRI);
-
-      alloc = nr_acknack_scheduling(nr_mac, UE, frameP, slotP, ra->beam_id, r_pucch, 1);
-      if (alloc < 0) {
-        LOG_D(NR_MAC,"Couldn't find a pucch allocation for ack nack (msg4) in frame %d slot %d\n", frameP, slotP);
-        reset_beam_status(&nr_mac->beam_info, frameP, slotP, ra->beam_id, n_slots_frame, beam.new_beam);
-        return;
-      }
-    }
-
     NR_UE_harq_t *harq = &sched_ctrl->harq_processes[current_harq_pid];
-    NR_sched_pucch_t *pucch = NULL;
+    NR_sched_pucch_t *pucch = &sched_ctrl->sched_pucch[alloc];
     DevAssert(!harq->is_waiting);
-    if (alloc < 0) {
-      finish_nr_dl_harq(sched_ctrl, current_harq_pid);
-    } else {
-      pucch = &sched_ctrl->sched_pucch[alloc];
-      add_tail_nr_list(&sched_ctrl->feedback_dl_harq, current_harq_pid);
-      harq->feedback_slot = pucch->ul_slot;
-      harq->feedback_frame = pucch->frame;
-      harq->is_waiting = true;
-    }
+    add_tail_nr_list(&sched_ctrl->feedback_dl_harq, current_harq_pid);
+    harq->feedback_slot = pucch->ul_slot;
+    harq->feedback_frame = pucch->frame;
+    harq->is_waiting = true;
     ra->harq_pid = current_harq_pid;
     UE->mac_stats.dl.rounds[harq->round]++;
-
     harq->tb_size = tb_size;
-
     uint8_t *buf = allocate_transportBlock_buffer(&harq->transportBlock, tb_size);
     // Bytes to be transmitted
     if (harq->round == 0) {
@@ -2293,29 +2280,14 @@ static void nr_generate_Msg4_MsgB(module_id_t module_idP,
       vrb_map[BWPStart + rb + rbStart] |= SL_to_bitmap(msg4_tda.startSymbolIndex, msg4_tda.nrOfSymbols);
     }
 
-    if (pucch == NULL) {
-      LOG_A(NR_MAC, "(UE RNTI 0x%04x) Skipping Ack of RA-Msg4. CBRA procedure succeeded!\n", ra->rnti);
-      UE->Msg4_MsgB_ACKed = true;
-
-      // Pause scheduling according to:
-      // 3GPP TS 38.331 Section 12 Table 12.1-1: UE performance requirements for RRC procedures for UEs
-      // Msg4 may transmit a RRCReconfiguration, for example when UE sends RRCReestablishmentComplete and MAC CE for C-RNTI in Msg3.
-      // In that case, gNB will generate a RRCReconfiguration that will be transmitted in Msg4, so we need to apply CellGroup after the Ack,
-      // UE->reconfigCellGroup was already set when processing RRCReestablishment message
-      int delay = nr_mac_get_reconfig_delay_slots(UE->current_UL_BWP.scs);
-      nr_mac_interrupt_ue_transmission(nr_mac, UE, UE->interrupt_action, delay);
-
-      nr_clear_ra_proc(ra);
-    } else {
-      ra->ra_state = nrRA_WAIT_Msg4_MsgB_ACK;
-      LOG_I(NR_MAC,
-            "UE %04x Generate %s: feedback at %4d.%2d, payload %d bytes, next state nrRA_WAIT_Msg4_MsgB_ACK\n",
-            ra->rnti,
-            ra_type_str,
-            pucch->frame,
-            pucch->ul_slot,
-            harq->tb_size);
-    }
+    ra->ra_state = nrRA_WAIT_Msg4_MsgB_ACK;
+    LOG_I(NR_MAC,
+          "UE %04x Generate %s: feedback at %4d.%2d, payload %d bytes, next state nrRA_WAIT_Msg4_MsgB_ACK\n",
+          ra->rnti,
+          ra_type_str,
+          pucch->frame,
+          pucch->ul_slot,
+          harq->tb_size);
   }
 }