rlc_am_lte: avoid locking of Rx mutex twice when generating status PDU

call reset_status(), which now is an private method directly when
building a status PDU. No need for the Tx side to call Rx again.

lib/include/srsran/rlc/rlc_am_lte.h

@@ -484,7 +484,6 @@ private:
     int  get_status_pdu_length();
     int  get_status_pdu(rlc_status_pdu_t* status, const uint32_t nof_bytes);
     bool get_do_status();
-    void reset_status(); // called when status PDU has been sent
 
   private:
     void handle_data_pdu(uint8_t* payload, uint32_t nof_bytes, rlc_amd_pdu_header_t& header);
@@ -494,6 +493,7 @@ private:
     void debug_state();
     void print_rx_segments();
     bool add_segment_and_check(rlc_amd_rx_pdu_segments_t* pdu, rlc_amd_rx_pdu* segment);
+    void reset_status();
 
     rlc_am_lte*           parent = nullptr;
     byte_buffer_pool*     pool   = nullptr;

lib/src/rlc/rlc_am_lte.cc

@@ -671,9 +671,6 @@ int rlc_am_lte::rlc_am_lte_tx::build_status_pdu(uint8_t* payload, uint32_t nof_b
     pdu_len = 0;
   } else if (pdu_len > 0 && nof_bytes >= static_cast<uint32_t>(pdu_len)) {
     log_rlc_am_status_pdu_to_string(logger.info, "%s Tx status PDU - %s", &tx_status, RB_NAME);
-
-    parent->rx.reset_status();
-
     if (cfg.t_status_prohibit > 0 && status_prohibit_timer.is_valid()) {
       // re-arm timer
       status_prohibit_timer.run();
@@ -1845,7 +1842,6 @@ void rlc_am_lte::rlc_am_lte_rx::reassemble_rx_sdus()
 
 void rlc_am_lte::rlc_am_lte_rx::reset_status()
 {
-  std::lock_guard<std::mutex> lock(mutex);
   do_status     = false;
   poll_received = false;
 }
@@ -1970,6 +1966,9 @@ int rlc_am_lte::rlc_am_lte_rx::get_status_pdu(rlc_status_pdu_t* status, const ui
     i = (i + 1) % MOD;
   }
 
+  // valid PDU could be generated
+  reset_status();
+
   return rlc_am_packed_length(status);
 }