From 08e93cdc3fe54df7753170e973d119c6bbbb6181 Mon Sep 17 00:00:00 2001
From: Andreas Eversberg <jolly@eversberg.eu>
Date: Thu, 26 Jul 2012 08:13:06 +0200
Subject: [PATCH] Use final_ack_sent and contention_resolution_done to define
 ongoing UL TBF

Both flags can be used to determine wether assignment must be sent on PCH
or on AGCH. Before contention resolution is done, mobile will ignore
downlink assinment. When final uplink acknowledge was sent, the mobile
will go back to PCH after reception of akcnowledge.
---
 src/gprs_bssgp_pcu.cpp   | 5 ++---
 src/gprs_rlcmac.h        | 3 ++-
 src/gprs_rlcmac_data.cpp | 7 ++++---
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/gprs_bssgp_pcu.cpp b/src/gprs_bssgp_pcu.cpp
index c4d27e85..9b977f29 100644
--- a/src/gprs_bssgp_pcu.cpp
+++ b/src/gprs_bssgp_pcu.cpp
@@ -177,9 +177,8 @@ int gprs_bssgp_pcu_rx_dl_ud(struct msgb *msg, struct tlv_parsed *tp)
 
 		/* check for uplink data, so we copy our informations */
 		tbf = tbf_by_tlli(tlli, GPRS_RLCMAC_UL_TBF);
-		if (tbf && tbf->contention_resolution_done
-		 && (tbf->state != GPRS_RLCMAC_FINISHED
-		  || tbf->ul_ack_state != GPRS_RLCMAC_UL_ACK_WAIT_ACK)) {
+		if (tbf && tbf->dir.ul.contention_resolution_done
+		 && !tbf->dir.ul.final_ack_sent) {
 			use_trx = tbf->trx;
 			first_ts = tbf->first_ts;
 			ta = tbf->ta;
diff --git a/src/gprs_rlcmac.h b/src/gprs_rlcmac.h
index 7291f77a..fc4173de 100644
--- a/src/gprs_rlcmac.h
+++ b/src/gprs_rlcmac.h
@@ -139,7 +139,6 @@ struct gprs_rlcmac_tbf {
 	uint8_t tfi;
 	uint32_t tlli;
 	uint8_t tlli_valid;
-	uint8_t contention_resolution_done; /* set after done */
 	uint8_t trx;
 	uint16_t arfcn;
 	uint8_t tsc;
@@ -187,6 +186,8 @@ struct gprs_rlcmac_tbf {
 			int32_t rx_counter; /* count all received blocks */
 			uint8_t n3103;	/* N3103 counter */
 			uint8_t usf[8];	/* list USFs per PDCH (timeslot) */
+			uint8_t contention_resolution_done; /* set after done */
+			uint8_t final_ack_sent; /* set if we sent final ack */
 		} ul;
 	} dir;
 	uint8_t rlc_block[RLC_MAX_SNS/2][RLC_MAX_LEN]; /* block history */
diff --git a/src/gprs_rlcmac_data.cpp b/src/gprs_rlcmac_data.cpp
index 58985e0d..69cfe136 100644
--- a/src/gprs_rlcmac_data.cpp
+++ b/src/gprs_rlcmac_data.cpp
@@ -256,7 +256,7 @@ uplink_request:
 			}
 			ul_tbf->tlli = tbf->tlli;
 			ul_tbf->tlli_valid = 1; /* no contention resolution */
-			ul_tbf->contention_resolution_done = 1;
+			ul_tbf->dir.ul.contention_resolution_done = 1;
 			ul_tbf->ta = tbf->ta; /* use current TA */
 			tbf_new_state(ul_tbf, GPRS_RLCMAC_ASSIGN);
 			tbf_timer_start(ul_tbf, 3169, bts->t3169, 0);
@@ -586,13 +586,14 @@ struct msgb *gprs_rlcmac_send_uplink_ack(struct gprs_rlcmac_tbf *tbf,
 
 	/* now we must set this flag, so we are allowed to assign downlink
 	 * TBF on PACCH. it is only allowed when TLLI is aknowledged. */
-	tbf->contention_resolution_done = 1;
+	tbf->dir.ul.contention_resolution_done = 1;
 
 	if (final) {
 		tbf->poll_state = GPRS_RLCMAC_POLL_SCHED;
 		tbf->poll_fn = (fn + 13) % 2715648;
 		/* waiting for final acknowledge */
 		tbf->ul_ack_state = GPRS_RLCMAC_UL_ACK_WAIT_ACK;
+		tbf->dir.ul.final_ack_sent = 1;
 	} else
 		tbf->ul_ack_state = GPRS_RLCMAC_UL_ACK_NONE;
 
@@ -1432,7 +1433,7 @@ struct msgb *gprs_rlcmac_send_packet_downlink_assignment(
 	if (tbf->direction == GPRS_RLCMAC_UL_TBF) {
 		/* be sure to check first, if contention resolution is done,
 		 * otherwise we cannot send the assignment yet */
-		if (!tbf->contention_resolution_done) {
+		if (!tbf->dir.ul.contention_resolution_done) {
 			LOGP(DRLCMAC, LOGL_DEBUG, "Cannot assign DL TBF now, "
 				"because contention resolution is not "
 				"finished.\n");