From 1a5f10be90bf9dac9c7d42c645f28c1df642b822 Mon Sep 17 00:00:00 2001
From: Cedric Roux <cedric.roux@eurecom.fr>
Date: Tue, 6 Apr 2021 10:38:28 +0200
Subject: [PATCH] bugfix: nr: free RA process when UE is removed

The bug was:
connect a phone, disconnect, repeat five times. The fifth time the phone
does not reconnect because there is no free RA process.

When an UE is removed, we have to free associated RA processes.
---
 .../LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c  | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c
index 94524795f3..9db78244ba 100644
--- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c
+++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c
@@ -1705,6 +1705,7 @@ void mac_remove_nr_ue(module_id_t mod_id, rnti_t rnti)
 {
   int UE_id;
   int i;
+  int cc_id;
   NR_UE_info_t *UE_info = &RC.nrmac[mod_id]->UE_info;
 
   for (i = 0; i < MAX_MOBILES_PER_GNB; i++) {
@@ -1741,6 +1742,20 @@ void mac_remove_nr_ue(module_id_t mod_id, rnti_t rnti)
     rnti_to_remove_count++;
     if (pthread_mutex_unlock(&rnti_to_remove_mutex)) exit(1);
   }
+
+  /* clear RA process(es?) associated to the UE */
+  for (cc_id = 0; cc_id < NFAPI_CC_MAX; cc_id++) {
+    NR_COMMON_channels_t *cc = &RC.nrmac[mod_id]->common_channels[cc_id];
+    for (i = 0; i < NR_NB_RA_PROC_MAX; i++) {
+      if (cc->ra[i].rnti == rnti) {
+        LOG_D(MAC, "free RA process %d for rnti %d\n", i, rnti);
+        /* is it enough? */
+        cc->ra[i].cfra  = false;
+        cc->ra[i].rnti  = 0;
+        cc->ra[i].crnti = 0;
+      }
+    }
+  }
 }
 
 uint8_t nr_get_tpc(int target, uint8_t cqi, int incr) {