Trigger RX processing after scheduler has been triggered

The scheduler prepares PRACH/PUSCH/PUCCH FAPI PDUs. As of this commit,
the scheduler runs in the TX processing chain, whereas these PDUs are
destined for RX processing.

To avoid data races, instead of triggering the RX processing at the same
time as TX processing in the RU thread, this commit changes the code to
trigger RX processing after the scheduler has been run in TX processing
to avoid data races.

executables/nr-gnb.c

@@ -112,12 +112,14 @@ time_stats_t softmodem_stats_rx_sf; // total rx time
 #define L1STATSSTRLEN 16384
 
 
-void tx_func(void *param) 
+static void tx_func(void *param)
 {
   processingData_L1tx_t *info = (processingData_L1tx_t *) param;
 
   int frame_tx = info->frame;
   int slot_tx = info->slot;
+  int frame_rx = info->frame_rx;
+  int slot_rx = info->slot_rx;
   int absslot_tx = info->timestamp_tx / info->gNB->frame_parms.get_samples_per_slot(slot_tx, &info->gNB->frame_parms);
   int absslot_rx = absslot_tx - info->gNB->RU_list[0]->sl_ahead;
   int rt_prof_idx = absslot_rx % RT_PROF_DEPTH;
@@ -129,12 +131,26 @@ void tx_func(void *param)
   NR_IF_Module_t *ifi = gNB->if_inst;
   nfapi_nr_config_request_scf_t *cfg = &gNB->gNB_config;
 
-  if (absslot_tx >= 2000) {
+  T(T_GNB_PHY_DL_TICK, T_INT(gNB->Mod_id), T_INT(frame_tx), T_INT(slot_tx));
+
+  if (1) {
     ifi->NR_slot_indication(module_id, CC_id, frame_tx, slot_tx);
     gNB->msgDataTx->timestamp_tx = info->timestamp_tx;
     info = gNB->msgDataTx;
     info->gNB = gNB;
 
+    // At this point, MAC scheduler just ran, including scheduling
+    // PRACH/PUCCH/PUSCH, so trigger RX chain processing
+    LOG_D(NR_PHY, "%s() trigger RX\n", __func__);
+    notifiedFIFO_elt_t *res = newNotifiedFIFO_elt(sizeof(processingData_L1_t), 0, &gNB->resp_L1, NULL);
+    processingData_L1_t *syncMsg = NotifiedFifoData(res);
+    syncMsg->gNB = gNB;
+    syncMsg->frame_rx = frame_rx;
+    syncMsg->slot_rx = slot_rx;
+    syncMsg->timestamp_tx = info->timestamp_tx;
+    res->key = slot_rx;
+    pushNotifiedFIFO(&gNB->resp_L1, res);
+
     int tx_slot_type = nr_slot_select(cfg, frame_tx, slot_tx);
     if ((tx_slot_type == NR_DOWNLINK_SLOT || tx_slot_type == NR_MIXED_SLOT) && NFAPI_MODE != NFAPI_MODE_PNF) {
       start_meas(&info->gNB->phy_proc_tx);
@@ -192,8 +208,6 @@ void rx_func(void *param)
   PHY_VARS_gNB *gNB = info->gNB;
   int frame_rx = info->frame_rx;
   int slot_rx = info->slot_rx;
-  int frame_tx = info->frame_tx;
-  int slot_tx = info->slot_tx;
   nfapi_nr_config_request_scf_t *cfg = &gNB->gNB_config;
   int cumul_samples = gNB->frame_parms.get_samples_per_slot(0, &gNB->frame_parms);
   int i = 1;
@@ -218,10 +232,8 @@ void rx_func(void *param)
   }
   // ****************************************
 
-  T(T_GNB_PHY_DL_TICK, T_INT(gNB->Mod_id), T_INT(frame_tx), T_INT(slot_tx));
-
-  reset_active_stats(gNB, frame_tx);
-  reset_active_ulsch(gNB, frame_tx);
+  reset_active_stats(gNB, frame_rx);
+  reset_active_ulsch(gNB, frame_rx);
 
   // RX processing
   int rx_slot_type = nr_slot_select(cfg, frame_rx, slot_rx);
@@ -260,7 +272,6 @@ void rx_func(void *param)
   }
 
   stop_meas( &softmodem_stats_rxtx_sf );
-  LOG_D(PHY,"%s() Exit proc[rx:%d%d tx:%d%d]\n", __FUNCTION__, frame_rx, slot_rx, frame_tx, slot_tx);
   clock_gettime(CLOCK_MONOTONIC,&info->gNB->rt_L1_profiling.return_L1_RX[rt_prof_idx]);
 }
 

executables/nr-ru.c

@@ -1233,11 +1233,6 @@ void *ru_thread( void *param ) {
   pthread_mutex_unlock(&RC.ru_mutex);
   wait_sync("ru_thread");
 
-  processingData_L1_t *syncMsg;
-  processingData_L1tx_t *syncMsgTx;
-
-  notifiedFIFO_elt_t *res, *resTx = NULL;
-
   if(!emulate_rf) {
     // Start RF device if any
     if (ru->start_rf) {
@@ -1384,25 +1379,15 @@ void *ru_thread( void *param ) {
       }
     } // end if (slot_type == NR_UPLINK_SLOT || slot_type == NR_MIXED_SLOT) {
 
-    // At this point, all information for subframe has been received on FH interface
-    res = newNotifiedFIFO_elt(sizeof(processingData_L1_t), 0, &gNB->resp_L1, NULL);
-    resTx = newNotifiedFIFO_elt(sizeof(processingData_L1tx_t), 0, &gNB->L1_tx_out, NULL);
-    syncMsg = (processingData_L1_t *)NotifiedFifoData(res);
-    syncMsg->gNB = gNB;
-    syncMsg->frame_rx = proc->frame_rx;
-    syncMsg->slot_rx = proc->tti_rx;
-    syncMsg->frame_tx = proc->frame_tx;
-    syncMsg->slot_tx = proc->tti_tx;
-    syncMsg->timestamp_tx = proc->timestamp_tx;
-    res->key = proc->tti_rx;
-
-    syncMsgTx = (processingData_L1tx_t *)NotifiedFifoData(resTx);
+    notifiedFIFO_elt_t *resTx = newNotifiedFIFO_elt(sizeof(processingData_L1tx_t), 0, &gNB->L1_tx_out, NULL);
+    processingData_L1tx_t *syncMsgTx = NotifiedFifoData(resTx);
     syncMsgTx->gNB = gNB;
     syncMsgTx->frame = proc->frame_tx;
     syncMsgTx->slot = proc->tti_tx;
+    syncMsgTx->frame_rx = proc->frame_rx;
+    syncMsgTx->slot_rx = proc->tti_rx;
     syncMsgTx->timestamp_tx = proc->timestamp_tx;
     resTx->key = proc->tti_tx;
-    pushNotifiedFIFO(&gNB->resp_L1, res);
     pushNotifiedFIFO(&gNB->L1_tx_out, resTx);
   }
 

executables/softmodem-common.h

@@ -375,7 +375,6 @@ extern uint16_t sl_ahead;
 extern uint16_t sf_ahead;
 extern int oai_exit;
 
-void tx_func(void *param);
 void rx_func(void *param);
 void ru_tx_func(void *param);
 extern uint8_t nfapi_mode;

openair1/PHY/defs_gNB.h

@@ -793,9 +793,7 @@ union ldpcReqUnion {
 
 typedef struct processingData_L1 {
   int frame_rx;
-  int frame_tx;
   int slot_rx;
-  int slot_tx;
   openair0_timestamp timestamp_tx;
   PHY_VARS_gNB *gNB;
 } processingData_L1_t;
@@ -809,6 +807,8 @@ typedef enum {
 typedef struct processingData_L1tx {
   int frame;
   int slot;
+  int frame_rx;
+  int slot_rx;
   openair0_timestamp timestamp_tx;
   PHY_VARS_gNB *gNB;
   nfapi_nr_dl_tti_pdcch_pdu pdcch_pdu[NFAPI_NR_MAX_NB_CORESETS];