From 6f481e09f6aceefacca0e547ea7a4bb466a20864 Mon Sep 17 00:00:00 2001
From: francescomani <email@francescomani.it>
Date: Wed, 22 Jun 2022 16:15:31 +0200
Subject: [PATCH] abort rtx if RI decreased

---
 .../LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c   | 25 ++++++++++++++++++-
 .../LAYER2/NR_MAC_gNB/gNB_scheduler_uci.c     | 10 ++------
 openair2/LAYER2/NR_MAC_gNB/mac_proto.h        |  2 ++
 openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h       |  1 +
 4 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c
index 3b5c9ffad4..dce798f24f 100644
--- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c
+++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c
@@ -365,6 +365,18 @@ void nr_store_dlsch_buffer(module_id_t module_id,
   }
 }
 
+void abort_nr_dl_harq(NR_UE_info_t* UE, int8_t harq_pid) {
+
+  NR_UE_sched_ctrl_t *sched_ctrl = &UE->UE_sched_ctrl;
+  NR_UE_harq_t *harq = &sched_ctrl->harq_processes[harq_pid];
+
+  harq->ndi ^= 1;
+  harq->round = 0;
+  UE->mac_stats.dl.errors++;
+  add_tail_nr_list(&sched_ctrl->available_dl_harq, harq_pid);
+
+}
+
 bool allocate_dl_retransmission(module_id_t module_id,
                                 frame_t frame,
                                 sub_frame_t slot,
@@ -378,6 +390,16 @@ bool allocate_dl_retransmission(module_id_t module_id,
   NR_UE_sched_ctrl_t *sched_ctrl = &UE->UE_sched_ctrl;
   NR_sched_pdsch_t *retInfo = &sched_ctrl->harq_processes[current_harq_pid].sched_pdsch;
   NR_CellGroupConfig_t *cg = UE->CellGroup;
+  NR_pdsch_semi_static_t *ps = &sched_ctrl->pdsch_semi_static;
+
+  //TODO remove this and handle retransmission with old nrOfLayers
+  //     once ps structure is removed
+  if(ps->nrOfLayers < retInfo->nrOfLayers) {
+    LOG_W(NR_MAC,"Cannot schedule retransmission. RI changed from %d to %d\n",
+          retInfo->nrOfLayers, ps->nrOfLayers);
+    abort_nr_dl_harq(UE, current_harq_pid);
+    return false;
+  }
 
   NR_BWP_DownlinkDedicated_t *bwpd =
       cg &&
@@ -401,7 +423,6 @@ bool allocate_dl_retransmission(module_id_t module_id,
   const uint16_t bwpSize = coresetid == 0 ? RC.nrmac[module_id]->cset0_bwp_size : NRRIV2BW(genericParameters->locationAndBandwidth, MAX_BWP_SIZE);
 
   int rbStart = 0; // start wrt BWPstart
-  NR_pdsch_semi_static_t *ps = &sched_ctrl->pdsch_semi_static;
   int rbSize = 0;
   const int tda = get_dl_tda(RC.nrmac[module_id], scc, slot);
   AssertFatal(tda>=0,"Unable to find PDSCH time domain allocation in list\n");
@@ -1355,6 +1376,8 @@ void nr_schedule_ue_spec(module_id_t module_id,
       /* save which time allocation has been used, to be used on
        * retransmissions */
       harq->sched_pdsch.time_domain_allocation = ps->time_domain_allocation;
+      /* save nr of layers for retransmissions */
+      harq->sched_pdsch.nrOfLayers = ps->nrOfLayers;
 
       // ta command is sent, values are reset
       if (sched_ctrl->ta_apply) {
diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_uci.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_uci.c
index d64b9c43db..a9a67141a2 100644
--- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_uci.c
+++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_uci.c
@@ -826,14 +826,8 @@ static void handle_dl_harq(NR_UE_info_t * UE,
     harq->ndi ^= 1;
 
   } else if (harq->round >= harq_round_max - 1) {
-    add_tail_nr_list(&UE->UE_sched_ctrl.available_dl_harq, harq_pid);
-    harq->round = 0;
-    harq->ndi ^= 1;
-
-    NR_mac_stats_t *stats = &UE->mac_stats;
-    stats->dl.errors++;
-    LOG_D(NR_MAC, "retransmission error for UE %04x (total %"PRIu64")\n", UE->rnti, stats->dl.errors);
-
+    abort_nr_dl_harq(UE, harq_pid);
+    LOG_D(NR_MAC, "retransmission error for UE %04x (total %"PRIu64")\n", UE->rnti, UE->mac_stats.dl.errors);
   } else {
     LOG_D(PHY,"NACK for: pid %d, ue %04x\n",harq_pid, UE->rnti);
     add_tail_nr_list(&UE->UE_sched_ctrl.retrans_dl_harq, harq_pid);
diff --git a/openair2/LAYER2/NR_MAC_gNB/mac_proto.h b/openair2/LAYER2/NR_MAC_gNB/mac_proto.h
index 7911275f70..bf36264b9d 100644
--- a/openair2/LAYER2/NR_MAC_gNB/mac_proto.h
+++ b/openair2/LAYER2/NR_MAC_gNB/mac_proto.h
@@ -532,4 +532,6 @@ size_t dump_mac_stats(gNB_MAC_INST *gNB, char *output, size_t strlen, bool reset
 
 void process_CellGroup(NR_CellGroupConfig_t *CellGroup, NR_UE_sched_ctrl_t *sched_ctrl);
 
+void abort_nr_dl_harq(NR_UE_info_t* UE, int8_t harq_pid);
+
 #endif /*__LAYER2_NR_MAC_PROTO_H__*/
diff --git a/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h b/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
index 7658441aed..049c7547ec 100644
--- a/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
+++ b/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
@@ -440,6 +440,7 @@ typedef struct NR_sched_pdsch {
   /// only important for retransmissions; otherwise, the TDA in
   /// NR_pdsch_semi_static_t has precedence
   int time_domain_allocation;
+  uint8_t nrOfLayers;
 } NR_sched_pdsch_t;
 
 typedef struct NR_UE_harq {