From d7f6820d1237306c86431f3dc05743967672f131 Mon Sep 17 00:00:00 2001
From: Ismael Gomez <ismael@softwareradiosystems.com>
Date: Wed, 6 Jun 2018 21:36:52 -0700
Subject: [PATCH] Reorder UE remove procedure to avoid mutex in RLC/PDCP

---
 srsenb/src/upper/rrc.cc | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/srsenb/src/upper/rrc.cc b/srsenb/src/upper/rrc.cc
index 19a8dc073..4a1477a2d 100644
--- a/srsenb/src/upper/rrc.cc
+++ b/srsenb/src/upper/rrc.cc
@@ -308,16 +308,22 @@ void rrc::rem_user(uint16_t rnti)
   if (users.count(rnti) == 1) {
     rrc_log->console("Disconnecting rnti=0x%x.\n", rnti);
     rrc_log->info("Disconnecting rnti=0x%x.\n", rnti);
-    /* **Caution** order of removal here is important: from bottom to top */
+
+    /* First remove MAC and GTPU to stop processing DL/UL traffic for this user
+     */
     mac->ue_rem(rnti);  // MAC handles PHY
+    gtpu->rem_user(rnti);
 
+    // Wait enough time
     pthread_mutex_unlock(&user_mutex);
     usleep(50000);
     pthread_mutex_lock(&user_mutex);
 
+    // Now remove RLC and PDCP
     rlc->rem_user(rnti);
     pdcp->rem_user(rnti);
-    gtpu->rem_user(rnti);
+
+    // And deallocate resources from RRC
     users[rnti].sr_free();
     users[rnti].cqi_free();
     users.erase(rnti);