implement harq resuming functionality

srsenb/hdr/stack/mac/scheduler_ue.h

@@ -245,7 +245,7 @@ public:
   cc_sched_ue*                     find_ue_carrier(uint32_t enb_cc_idx);
   size_t                           nof_carriers_configured() const { return carriers.size(); }
   std::bitset<SRSLTE_MAX_CARRIERS> scell_activation_mask() const;
-  int                              find_enb_cc_idx(uint32_t enb_cc_idx) const;
+  int                              enb_to_ue_cc_idx(uint32_t enb_cc_idx) const;
 
   bool     needs_cqi(uint32_t tti, uint32_t cc_idx, bool will_send = false);
   uint32_t get_max_retx();

srsenb/src/stack/mac/scheduler_grid.cc

@@ -600,7 +600,8 @@ void sf_sched::new_tti(tti_point tti_rx_, sf_sched_result* cc_results_)
     prbmask_t prach_mask{cc_cfg->nof_prb()};
     prach_mask.fill(cc_cfg->cfg.prach_freq_offset, cc_cfg->cfg.prach_freq_offset + 6);
     reserve_ul_prbs(prach_mask, cc_cfg->nof_prb() != 6);
-    log_h->debug("SCHED: Allocated PRACH RBs. Mask: 0x%s\n", prach_mask.to_hex().c_str());
+    log_h->debug(
+        "SCHED: Allocated PRACH RBs for tti_tx_ul=%d. Mask: 0x%s\n", tti_params.tti_tx_ul, prach_mask.to_hex().c_str());
   }
 
   // setup first prb to be used for msg3 alloc. Account for potential PRACH alloc
@@ -770,7 +771,7 @@ alloc_outcome_t sf_sched::alloc_dl_user(sched_ue* user, const rbgmask_t& user_ma
   }
 
   // Check if allocation would cause segmentation
-  uint32_t            ue_cc_idx = user->find_enb_cc_idx(cc_cfg->enb_cc_idx);
+  uint32_t            ue_cc_idx = user->enb_to_ue_cc_idx(cc_cfg->enb_cc_idx);
   const dl_harq_proc& h         = user->get_dl_harq(pid, ue_cc_idx);
   if (h.is_empty()) {
     // It is newTx
@@ -1227,6 +1228,23 @@ void sf_sched::generate_sched_results(sched_ue_list& ue_db)
 {
   cc_sched_result* cc_result = cc_results->get_cc(cc_cfg->enb_cc_idx);
 
+  /* Resume UL HARQs with pending retxs that did not get allocated */
+  using phich_t    = sched_interface::ul_sched_phich_t;
+  auto& phich_list = cc_result->ul_sched_result.phich;
+  for (uint32_t i = 0; i < cc_result->ul_sched_result.nof_phich_elems; ++i) {
+    auto& phich = phich_list[i];
+    if (phich.phich == phich_t::NACK) {
+      auto&         ue        = ue_db[phich.rnti];
+      int           ue_cc_idx = ue.enb_to_ue_cc_idx(cc_cfg->enb_cc_idx);
+      ul_harq_proc* h         = (ue_cc_idx >= 0) ? ue.get_ul_harq(get_tti_tx_ul(), ue_cc_idx) : nullptr;
+      if (not is_ul_alloc(ue.get_rnti()) and h != nullptr and not h->is_empty()) {
+        // There was a missed UL harq retx. Halt+Resume the HARQ
+        phich.phich = phich_t::ACK;
+        log_h->debug("SCHED: rnti=0x%x UL harq pid=%d is being resumed\n", ue.get_rnti(), h->get_id());
+      }
+    }
+  }
+
   /* Pick one of the possible DCI masks */
   pdcch_grid_t::alloc_result_t dci_result;
   //  tti_alloc.get_pdcch_grid().result_to_string();

srsenb/src/stack/mac/scheduler_ue.cc

@@ -1200,7 +1200,7 @@ sched_dci_cce_t* sched_ue::get_locations(uint32_t enb_cc_idx, uint32_t cfi, uint
 
 cc_sched_ue* sched_ue::find_ue_carrier(uint32_t enb_cc_idx)
 {
-  int ue_cc_idx = find_enb_cc_idx(enb_cc_idx);
+  int ue_cc_idx = enb_to_ue_cc_idx(enb_cc_idx);
   return ue_cc_idx >= 0 ? &carriers[ue_cc_idx] : nullptr;
 }
 
@@ -1215,7 +1215,7 @@ std::bitset<SRSLTE_MAX_CARRIERS> sched_ue::scell_activation_mask() const
   return ret;
 }
 
-int sched_ue::find_enb_cc_idx(uint32_t enb_cc_idx) const
+int sched_ue::enb_to_ue_cc_idx(uint32_t enb_cc_idx) const
 {
   auto it = std::find_if(carriers.begin(), carriers.end(), [enb_cc_idx](const cc_sched_ue& c) {
     return c.get_cell_cfg()->enb_cc_idx == enb_cc_idx;

srsenb/test/mac/scheduler_test_rand.cc

@@ -324,7 +324,15 @@ int sched_tester::test_harqs()
     CONDERROR(not hprev.has_pending_ack(), "Alloc PHICH did not have any pending ack\n");
     bool maxretx_flag = hprev.nof_retx(0) + 1 >= hprev.max_nof_retx();
     if (phich.phich == sched_interface::ul_sched_phich_t::ACK) {
-      CONDERROR(!hprev.is_empty(), "ack phich for UL harq that is not empty\n");
+      // The harq can be either ACKed or Resumed
+      if (not hprev.is_empty()) {
+        // In case it was resumed
+        CONDERROR(h == nullptr or h->is_empty(), "Cannot resume empty UL harq\n");
+        for (uint32_t j = 0; j < tti_info.ul_sched_result[CARRIER_IDX].nof_dci_elems; ++j) {
+          auto& pusch = tti_info.ul_sched_result[CARRIER_IDX].pusch[j];
+          CONDERROR(pusch.dci.rnti == phich.rnti, "Cannot send PHICH::ACK for same harq that got UL grant.\n");
+        }
+      }
     } else {
       CONDERROR(h->get_pending_data() == 0 and !maxretx_flag, "NACKed harq has no pending data\n");
     }