nr: pdcp: accept "infinity" for t-reordering

"infinity" is -1 in the code.

openair2/LAYER2/nr_pdcp/nr_pdcp_entity.c

@@ -217,6 +217,10 @@ static void check_t_reordering(nr_pdcp_entity_t *entity)
 {
   uint32_t count;
 
+  /* if t_reordering is set to "infinity" (seen as -1) then do nothing */
+  if (entity->t_reordering == -1)
+    return;
+
   if (entity->t_reordering_start == 0
       || entity->t_current <= entity->t_reordering_start + entity->t_reordering)
     return;

openair2/LAYER2/nr_pdcp/nr_pdcp_entity.h

@@ -55,8 +55,8 @@ typedef struct nr_pdcp_entity_t {
   int rb_id;
 
   int sn_size;                  /* SN size, in bits */
-  int t_reordering;             /* unit: ms */
-  int discard_timer;            /* unit: ms */
+  int t_reordering;             /* unit: ms, -1 for infinity */
+  int discard_timer;            /* unit: ms, -1 for infinity */
 
   int sn_max;                   /* (2^SN_size) - 1 */
   int window_size;              /* 2^(SN_size - 1) */

openair2/LAYER2/nr_pdcp/nr_pdcp_oai_api.c

@@ -610,11 +610,17 @@ static void add_drb_am(int is_gnb, int rnti, struct NR_DRB_ToAddMod *s,
   nr_pdcp_ue_t *ue;
 
   int drb_id = s->drb_Identity;
-  int t_reordering = decode_t_reordering(*s->pdcp_Config->t_Reordering);
+  int t_reordering;
   int sn_size_ul = decode_sn_size_ul(*s->pdcp_Config->drb->pdcp_SN_SizeUL);
   int sn_size_dl = decode_sn_size_dl(*s->pdcp_Config->drb->pdcp_SN_SizeDL);
   int discard_timer = decode_discard_timer(*s->pdcp_Config->drb->discardTimer);
 
+  /* if pdcp_Config->t_Reordering is not present, it means infinity (-1) */
+  if (s->pdcp_Config->t_Reordering != NULL)
+    t_reordering = decode_t_reordering(*s->pdcp_Config->t_Reordering);
+  else
+    t_reordering = -1;
+
   /* TODO(?): accept different UL and DL SN sizes? */
   if (sn_size_ul != sn_size_dl) {
     LOG_E(PDCP, "%s:%d:%s: fatal, bad SN sizes, must be same. ul=%d, dl=%d\n",