[osmo-pcu 3/3] bts: Split tbf_by_poll_fn into separate dl and ul functions

[Daniel Willmann]

rcv_control_dl_ack_nack is only meaningful for dl tbf while
rcv_control_ack can be sent in response to a dl or ul tbf. So
rcv_control_ack still needs to check for ul and dl tbfs.

Ticket: SYS#389
Sponsored-by: On-Waves ehf
---
 src/bts.cpp | 21 ++++++++++++++++-----
 src/bts.h   |  3 ++-
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/src/bts.cpp b/src/bts.cpp
index 52960cf..08baee0 100644
--- a/src/bts.cpp
+++ b/src/bts.cpp
@@ -248,20 +248,28 @@ gprs_rlcmac_tbf *BTS::tbf_by_tlli(uint32_t tlli, enum 
gprs_rlcmac_tbf_direction
        return NULL;
 }
 
-gprs_rlcmac_tbf *BTS::tbf_by_poll_fn(uint32_t fn, uint8_t trx, uint8_t ts)
+gprs_rlcmac_tbf *BTS::dl_tbf_by_poll_fn(uint32_t fn, uint8_t trx, uint8_t ts)
 {
        struct gprs_rlcmac_tbf *tbf;
 
        /* only one TBF can poll on specific TS/FN, because scheduler can only
         * schedule one downlink control block (with polling) at a FN per TS */
-       llist_for_each_entry(tbf, &m_bts.ul_tbfs, list) {
+       llist_for_each_entry(tbf, &m_bts.dl_tbfs, list) {
                if (tbf->state_is_not(GPRS_RLCMAC_RELEASING)
                 && tbf->poll_state == GPRS_RLCMAC_POLL_SCHED
                 && tbf->poll_fn == fn && tbf->trx->trx_no == trx
                 && tbf->control_ts == ts)
                        return tbf;
        }
-       llist_for_each_entry(tbf, &m_bts.dl_tbfs, list) {
+       return NULL;
+}
+gprs_rlcmac_tbf *BTS::ul_tbf_by_poll_fn(uint32_t fn, uint8_t trx, uint8_t ts)
+{
+       struct gprs_rlcmac_tbf *tbf;
+
+       /* only one TBF can poll on specific TS/FN, because scheduler can only
+        * schedule one downlink control block (with polling) at a FN per TS */
+       llist_for_each_entry(tbf, &m_bts.ul_tbfs, list) {
                if (tbf->state_is_not(GPRS_RLCMAC_RELEASING)
                 && tbf->poll_state == GPRS_RLCMAC_POLL_SCHED
                 && tbf->poll_fn == fn && tbf->trx->trx_no == trx
@@ -718,7 +726,10 @@ void 
gprs_rlcmac_pdch::rcv_control_ack(Packet_Control_Acknowledgement_t *packet,
        uint32_t tlli = 0;
 
        tlli = packet->TLLI;
-       tbf = bts()->tbf_by_poll_fn(fn, trx_no(), ts_no);
+       tbf = bts()->ul_tbf_by_poll_fn(fn, trx_no(), ts_no);
+       if (!tbf)
+               tbf = bts()->dl_tbf_by_poll_fn(fn, trx_no(), ts_no);
+
        if (!tbf) {
                LOGP(DRLCMAC, LOGL_NOTICE, "PACKET CONTROL ACK with "
                        "unknown FN=%u TLLI=0x%08x (TRX %d TS %d)\n",
@@ -804,7 +815,7 @@ void 
gprs_rlcmac_pdch::rcv_control_dl_ack_nack(Packet_Downlink_Ack_Nack_t *ack_n
        int rc;
 
        tfi = ack_nack->DOWNLINK_TFI;
-       tbf = bts()->tbf_by_poll_fn(fn, trx_no(), ts_no);
+       tbf = bts()->dl_tbf_by_poll_fn(fn, trx_no(), ts_no);
        if (!tbf) {
                LOGP(DRLCMAC, LOGL_NOTICE, "PACKET DOWNLINK ACK with "
                        "unknown FN=%u TFI=%d (TRX %d TS %d)\n",
diff --git a/src/bts.h b/src/bts.h
index a67f215..621bcba 100644
--- a/src/bts.h
+++ b/src/bts.h
@@ -194,7 +194,8 @@ public:
 
        gprs_rlcmac_tbf *dl_tbf_by_tlli(uint32_t tlli);
        gprs_rlcmac_tbf *ul_tbf_by_tlli(uint32_t tlli);
-       gprs_rlcmac_tbf *tbf_by_poll_fn(uint32_t fn, uint8_t trx, uint8_t ts);
+       gprs_rlcmac_tbf *dl_tbf_by_poll_fn(uint32_t fn, uint8_t trx, uint8_t 
ts);
+       gprs_rlcmac_tbf *ul_tbf_by_poll_fn(uint32_t fn, uint8_t trx, uint8_t 
ts);
        gprs_rlcmac_tbf *dl_tbf_by_tfi(uint8_t tfi, uint8_t trx);
        gprs_rlcmac_tbf *ul_tbf_by_tfi(uint8_t tfi, uint8_t trx);
 
-- 
1.8.4.2