From 240eba2af56b439f4b4b67f432d182bf9c997f29 Mon Sep 17 00:00:00 2001
From: Ismael Gomez <ismagom@gmail.com>
Date: Wed, 18 Oct 2017 16:49:36 -0400
Subject: [PATCH] Fix for async dl scheduling

---
 lib/include/srslte/common/common.h |  1 +
 srsue/hdr/mac/mac.h                |  2 +-
 srsue/src/phy/phch_worker.cc       | 11 +++++++----
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/lib/include/srslte/common/common.h b/lib/include/srslte/common/common.h
index 6372af73e..fbc703486 100644
--- a/lib/include/srslte/common/common.h
+++ b/lib/include/srslte/common/common.h
@@ -52,6 +52,7 @@
 #define TTIMOD_SZ       (((2*HARQ_DELAY_MS) < 10)?10:20)
 #define TTIMOD(tti)     (tti%TTIMOD_SZ)
 
+#define MOD_N_PROC      (2*HARQ_DELAY_MS-8)
 #define ASYNC_DL_SCHED  (HARQ_DELAY_MS <= 4)
 
 // Cat 3 UE - Max number of DL-SCH transport block bits received within a TTI
diff --git a/srsue/hdr/mac/mac.h b/srsue/hdr/mac/mac.h
index d19f668bf..87bb764e1 100644
--- a/srsue/hdr/mac/mac.h
+++ b/srsue/hdr/mac/mac.h
@@ -135,7 +135,7 @@ private:
   demux         demux_unit; 
   
   /* DL/UL HARQ */
-  dl_harq_entity<MAC_NOF_HARQ_PROC, mac_grant_t, tb_action_dl_t, srslte_phy_grant_t> dl_harq;
+  dl_harq_entity<MAC_NOF_HARQ_PROC+MOD_N_PROC, mac_grant_t, tb_action_dl_t, srslte_phy_grant_t> dl_harq;
   ul_harq_entity<MAC_NOF_HARQ_PROC, mac_grant_t, tb_action_ul_t, srslte_phy_grant_t> ul_harq;
   
   /* MAC Uplink-related Procedures */
diff --git a/srsue/src/phy/phch_worker.cc b/srsue/src/phy/phch_worker.cc
index f89696015..a32bb7537 100644
--- a/srsue/src/phy/phch_worker.cc
+++ b/srsue/src/phy/phch_worker.cc
@@ -65,8 +65,7 @@ phch_worker::phch_worker() : tr_exec(10240)
   cell_initiated  = false; 
   pregen_enabled  = false; 
   trace_enabled   = false;
-
-  reset();  
+  reset();
 }
 
 
@@ -97,7 +96,7 @@ void phch_worker::reset()
   bzero(&period_cqi, sizeof(srslte_cqi_periodic_cfg_t));
   I_sr = 0; 
   rnti_is_set     = false; 
-  rar_cqi_request = false; 
+  rar_cqi_request = false;
   cfi = 0;
 }
 
@@ -482,7 +481,11 @@ bool phch_worker::decode_pdcch_dl(srsue::mac_interface_phy::mac_grant_t* grant)
     /* Fill MAC grant structure */
     grant->ndi[0] = dci_unpacked.ndi;
     grant->ndi[1] = dci_unpacked.ndi_1;
-    grant->pid = ASYNC_DL_SCHED?dci_unpacked.harq_process:(tti%(2*HARQ_DELAY_MS));
+    if (tti < MOD_N_PROC) {
+      grant->pid = ASYNC_DL_SCHED?dci_unpacked.harq_process:tti+(2*HARQ_DELAY_MS);
+    } else {
+      grant->pid = ASYNC_DL_SCHED?dci_unpacked.harq_process:(tti%(2*HARQ_DELAY_MS));
+    }
     grant->n_bytes[0] = grant->phy_grant.dl.mcs[0].tbs / (uint32_t) 8;
     grant->n_bytes[1] = grant->phy_grant.dl.mcs[1].tbs / (uint32_t) 8;
     grant->tti = tti;