From cbcd124588abf91be129aee3f37505ca60706de9 Mon Sep 17 00:00:00 2001
From: Andreas Eversberg <jolly@eversberg.eu>
Date: Tue, 7 Aug 2012 15:48:21 +0200
Subject: [PATCH] Fix: Add timer for downlink TBF in assignment state

This is required, since the UL TBF which is used to assign downlink TBF
may be freed due to timeouts.
---
 src/gprs_rlcmac.h        |  3 ++-
 src/gprs_rlcmac_data.cpp | 32 +++++++++++++++++++++++++-------
 2 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/src/gprs_rlcmac.h b/src/gprs_rlcmac.h
index 6bdef6be..e1c8343f 100644
--- a/src/gprs_rlcmac.h
+++ b/src/gprs_rlcmac.h
@@ -93,7 +93,8 @@ extern struct gprs_rlcmac_bts *gprs_rlcmac_bts;
 #define RLC_MAX_WS  64 /* max window size */
 #define RLC_MAX_LEN 54 /* CS-4 including spare bits */
 
-#define Tassign_agch 0,800000/* FIXME: we need a confirm from BTS */
+#define Tassign_agch 0,800000	/* FIXME: we need a confirm from BTS */
+#define Tassign_pacch 2,0	/* timeout for pacch assigment */
 
 enum gprs_rlcmac_tbf_state {
 	GPRS_RLCMAC_NULL = 0,	/* new created TBF */
diff --git a/src/gprs_rlcmac_data.cpp b/src/gprs_rlcmac_data.cpp
index d59153f7..a1bed3c6 100644
--- a/src/gprs_rlcmac_data.cpp
+++ b/src/gprs_rlcmac_data.cpp
@@ -247,6 +247,8 @@ int gprs_rlcmac_rcv_control_block(bitvec *rlc_block, uint8_t trx, uint8_t ts,
 				break;
 			}
 			tbf_new_state(tbf, GPRS_RLCMAC_FLOW);
+			/* stop pending assignment timer */
+			tbf_timer_stop(tbf);
 			if ((tbf->state_flags &
 				(1 << GPRS_RLCMAC_FLAG_TO_DL_ASS))) {
 				tbf->state_flags &=
@@ -405,13 +407,24 @@ void tbf_timer_cb(void *_tbf)
 		break;
 #endif
 	case 0: /* assignment */
-		/* change state to FLOW, so scheduler will start transmission */
-		if (tbf->state == GPRS_RLCMAC_ASSIGN) {
-			tbf_new_state(tbf, GPRS_RLCMAC_FLOW);
-			tbf_assign_control_ts(tbf);
-		} else
-			LOGP(DRLCMAC, LOGL_ERROR, "Error: TBF is not in assign "
-				"state\n");
+		if ((tbf->state_flags & (1 << GPRS_RLCMAC_FLAG_PACCH))) {
+			if (tbf->state == GPRS_RLCMAC_ASSIGN) {
+				LOGP(DRLCMAC, LOGL_NOTICE, "Releasing due to "
+					"PACCH assignment timeout.\n");
+				tbf_free(tbf);
+			} else
+				LOGP(DRLCMAC, LOGL_ERROR, "Error: TBF is not "
+					"in assign state\n");
+		}
+		if ((tbf->state_flags & (1 << GPRS_RLCMAC_FLAG_CCCH))) {
+			/* change state to FLOW, so scheduler will start transmission */
+			if (tbf->state == GPRS_RLCMAC_ASSIGN) {
+				tbf_new_state(tbf, GPRS_RLCMAC_FLOW);
+				tbf_assign_control_ts(tbf);
+			} else
+				LOGP(DRLCMAC, LOGL_ERROR, "Error: TBF is not "
+					"in assign state\n");
+		}
 		break;
 	case 3169:
 	case 3191:
@@ -1575,6 +1588,9 @@ struct msgb *gprs_rlcmac_send_packet_downlink_assignment(
 		tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_NONE;
 		tbf_new_state(new_tbf, GPRS_RLCMAC_FLOW);
 		tbf_assign_control_ts(new_tbf);
+		/* stop pending assignment timer */
+		tbf_timer_stop(new_tbf);
+
 	}
 
 	return msg;
@@ -1623,6 +1639,8 @@ void gprs_rlcmac_trigger_downlink_assignment(struct gprs_rlcmac_tbf *tbf,
 		/* change state */
 		tbf_new_state(tbf, GPRS_RLCMAC_ASSIGN);
 		tbf->state_flags |= (1 << GPRS_RLCMAC_FLAG_PACCH);
+		/* start timer */
+		tbf_timer_start(tbf, 0, Tassign_pacch);
 #endif
 	} else {
 		LOGP(DRLCMAC, LOGL_DEBUG, "Send dowlink assignment for TBF=%d on PCH, no TBF exist (IMSI=%s)\n", tbf->tfi, imsi);