lte,pdcp: silence error message when a reconfiguration of a PDCP entity is no-op

lib/include/srsran/interfaces/pdcp_interface_types.h

@@ -156,6 +156,15 @@ public:
 
   // TODO: Support the following configurations
   // bool do_rohc;
+
+  bool operator==(const pdcp_config_t& other) const
+  {
+    return bearer_id == other.bearer_id and rb_type == other.rb_type and tx_direction == other.tx_direction and
+           rx_direction == other.rx_direction and sn_len == other.sn_len and hdr_len_bytes == other.hdr_len_bytes and
+           t_reordering == other.t_reordering and discard_timer == other.discard_timer and rat == other.rat and
+           status_report_required == other.status_report_required;
+  }
+  bool operator!=(const pdcp_config_t& other) const { return not(*this == other); }
 };
 
 // Specifies in which direction security (integrity and ciphering) are enabled for PDCP

lib/src/pdcp/pdcp.cc

@@ -93,8 +93,7 @@ void pdcp::write_sdu_mch(uint32_t lcid, unique_byte_buffer_t sdu)
 int pdcp::add_bearer(uint32_t lcid, pdcp_config_t cfg)
 {
   if (valid_lcid(lcid)) {
-    logger.error("Bearer %s already configured.", rrc->get_rb_name(lcid));
-    return SRSRAN_ERROR;
+    return pdcp_array[lcid]->configure(cfg) ? SRSRAN_SUCCESS : SRSRAN_ERROR;
   }
 
   std::unique_ptr<pdcp_entity_base> entity;

lib/src/pdcp/pdcp_entity_lte.cc

@@ -51,6 +51,15 @@ pdcp_entity_lte::~pdcp_entity_lte()
 
 bool pdcp_entity_lte::configure(const pdcp_config_t& cnfg_)
 {
+  if (active) {
+    // Already configured
+    if (cnfg_ != cfg) {
+      logger.error("Bearer reconfiguration not supported. LCID=%d.", rrc->get_rb_name(lcid));
+      return false;
+    }
+    return true;
+  }
+
   cfg                          = cnfg_;
   maximum_pdcp_sn              = (1u << cfg.sn_len) - 1u;
   st.last_submitted_pdcp_rx_sn = maximum_pdcp_sn;

lib/src/pdcp/pdcp_entity_nr.cc

@@ -43,6 +43,15 @@ void pdcp_entity_nr::reestablish()
 
 bool pdcp_entity_nr::configure(const pdcp_config_t& cnfg_)
 {
+  if (active) {
+    // Already configured
+    if (cnfg_ != cfg) {
+      logger.error("Bearer reconfiguration not supported. LCID=%d.", rrc->get_rb_name(lcid));
+      return false;
+    }
+    return true;
+  }
+
   cfg         = cnfg_;
   window_size = 1 << (cfg.sn_len - 1);