Search correct UL HARQ, don't assert on late slot

At the time of this commit, the CI has realtime issues. This can mean
that the HARQ result is delivered in a delayed fashion. Before this
commit, we were asserting on whether the slot corresponds to the HARQ
process's expected feedback slot, but a particular feedback might be
delayed under realtime issues, and we actually don't care about the
timing since we get the HARQ process ID.

Instead, we loop through the HARQ processes for which we wait for a
feedback in the beginning until we have the right process (which did not
seem to cause a problem till now, but who knows.

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c

@@ -310,9 +310,6 @@ void handle_nr_ul_harq(module_id_t mod_id,
                        sub_frame_t slot,
                        const nfapi_nr_crc_t *crc_pdu)
 {
-  const NR_ServingCellConfigCommon_t *scc = RC.nrmac[mod_id]->common_channels->ServingCellConfigCommon;
-  const int num_slots = nr_slots_per_frame[*scc->ssbSubcarrierSpacing];
-
   int UE_id = find_nr_UE_id(mod_id, crc_pdu->rnti);
   if (UE_id < 0) {
     LOG_E(MAC, "%s(): unknown RNTI %04x in PUSCH\n", __func__, crc_pdu->rnti);
@@ -321,23 +318,23 @@ void handle_nr_ul_harq(module_id_t mod_id,
   NR_UE_info_t *UE_info = &RC.nrmac[mod_id]->UE_info;
   NR_UE_sched_ctrl_t *sched_ctrl = &UE_info->UE_sched_ctrl[UE_id];
 
-  const int8_t harq_pid = sched_ctrl->feedback_ul_harq.head;
-  if (crc_pdu->harq_id != harq_pid && harq_pid < 0) {
+  int8_t harq_pid = sched_ctrl->feedback_ul_harq.head;
+  while (crc_pdu->harq_id != harq_pid || harq_pid < 0) {
     LOG_W(MAC,
           "Unexpected ULSCH HARQ PID %d (have %d) for RNTI %04x (ignore this warning for RA)\n",
           crc_pdu->harq_id,
           harq_pid,
           crc_pdu->rnti);
-    return;
+    if (harq_pid < 0)
+      return;
+
+    remove_front_nr_list(&sched_ctrl->feedback_ul_harq);
+    sched_ctrl->ul_harq_processes[harq_pid].round++;
+    add_tail_nr_list(&sched_ctrl->retrans_ul_harq, harq_pid);
+    harq_pid = sched_ctrl->feedback_ul_harq.head;
   }
-  DevAssert(harq_pid == crc_pdu->harq_id);
   remove_front_nr_list(&sched_ctrl->feedback_ul_harq);
   NR_UE_ul_harq_t *harq = &sched_ctrl->ul_harq_processes[harq_pid];
-  const int feedback_slot = (slot - 1 + num_slots) % num_slots;
-  AssertFatal(harq->feedback_slot == feedback_slot,
-              "expected feedback slot %d, but found %d instead\n",
-              harq->feedback_slot,
-              feedback_slot);
   DevAssert(harq->is_waiting);
   harq->feedback_slot = -1;
   harq->is_waiting = false;