[osmo-pcu 2/3] tbf/bts, encoding: Keep track of WAIT_RELEASE state for DL assignment

The current code does not properly distinguish between DL assignments to reuse a tbf (after it was put in state WAIT_RELEASE) and DL assignments for an active tbf to change the allocation of the PDCH timeslots. This patch introduces a new variable was_releasing which remembers if trigger_dl_ass() was called with a tbf in state WAIT_RELEASE. In that case we have to set the CONTROL_ACK field in the download assignment. This should allow us to send DL assignments to change PDCH TS allocation of a tbf before we enter FLOW state. --- src/bts.cpp | 2 ++ src/encoding.cpp | 2 +- src/tbf.cpp | 3 ++- src/tbf.h | 4 ++++ 4 files changed, 9 insertions(+), 2 deletions(-) diff --git a/src/bts.cpp b/src/bts.cpp index 6c02408..9003099 100644 --- a/src/bts.cpp +++ b/src/bts.cpp @@ -474,6 +474,7 @@ void BTS::trigger_dl_ass( old_tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_SEND_ASS; /* use TA from old TBF */ tbf->ta = old_tbf->ta; + tbf->was_releasing = tbf->state_is(GPRS_RLCMAC_WAIT_RELEASE); /* change state */ tbf_new_state(tbf, GPRS_RLCMAC_ASSIGN); tbf->state_flags |= (1 << GPRS_RLCMAC_FLAG_PACCH); @@ -485,6 +486,7 @@ void BTS::trigger_dl_ass( LOGP(DRLCMAC, LOGL_ERROR, "No valid IMSI!\n"); return; } + tbf->was_releasing = tbf->state_is(GPRS_RLCMAC_WAIT_RELEASE); /* change state */ tbf_new_state(tbf, GPRS_RLCMAC_ASSIGN); tbf->state_flags |= (1 << GPRS_RLCMAC_FLAG_CCCH); diff --git a/src/encoding.cpp b/src/encoding.cpp index 51b0fbe..13848aa 100644 --- a/src/encoding.cpp +++ b/src/encoding.cpp @@ -267,7 +267,7 @@ void Encoding::write_packet_downlink_assignment(RlcMacDownlink_t * block, uint8_ block->u.Packet_Downlink_Assignment.MAC_MODE = 0x0; // Dynamic Allocation block->u.Packet_Downlink_Assignment.RLC_MODE = 0x0; // RLC acknowledged mode - block->u.Packet_Downlink_Assignment.CONTROL_ACK = old_downlink; // NW establishes no new DL TBF for the MS with running timer T3192 + block->u.Packet_Downlink_Assignment.CONTROL_ACK = tbf->was_releasing; // NW establishes no new DL TBF for the MS with running timer T3192 block->u.Packet_Downlink_Assignment.TIMESLOT_ALLOCATION = 0; // timeslot(s) for (tn = 0; tn < 8; tn++) { if (tbf->pdch[tn]) diff --git a/src/tbf.cpp b/src/tbf.cpp index b20d0fc..dd1f0fb 100644 --- a/src/tbf.cpp +++ b/src/tbf.cpp @@ -1405,6 +1405,8 @@ int gprs_rlcmac_tbf::maybe_start_new_window() /* report all outstanding packets as received */ gprs_rlcmac_received_lost(this, received, 0); + tbf_new_state(this, GPRS_RLCMAC_WAIT_RELEASE); + /* check for LLC PDU in the LLC Queue */ msg = llc_dequeue(gprs_bssgp_pcu_current_bctx()); if (!msg) { @@ -1414,7 +1416,6 @@ int gprs_rlcmac_tbf::maybe_start_new_window() tbf_timer_start(this, 3193, bts_data()->t3193_msec / 1000, (bts_data()->t3193_msec % 1000) * 1000); - tbf_new_state(this, GPRS_RLCMAC_WAIT_RELEASE); return 0; } diff --git a/src/tbf.h b/src/tbf.h index 24b98d2..0ee9718 100644 --- a/src/tbf.h +++ b/src/tbf.h @@ -217,6 +217,10 @@ struct gprs_rlcmac_tbf { * stops to iterate over all tbf in its current form */ enum gprs_rlcmac_tbf_state state; + /* Remember if the tbf was in wait_release state when we want to + * schedule a new dl assignment */ + uint8_t was_releasing; + /* store the BTS this TBF belongs to */ BTS *bts; -- 1.8.4.2