Move GPRS_RLCMAC_FLAG_TO_DL_ACK from state_fsm to dl_tbf

That flag was still in state_fsm for historical reasons (refactoring
steps), but it's not really the best place for it, since it's really
specific to dl_tbf and to transmit of data and DL ACK/NACK not the
overall state of the TBF.

Change-Id: I6b44121bbe185b58f3a77be8c12b4ef1f3180a30

4 files changed, 11 insertions, 9 deletions

diff --git a/src/tbf.cpp b/src/tbf.cpp
index 885c6029..8981615f 100644
--- a/src/tbf.cpp
+++ b/src/tbf.cpp
@@ -560,11 +560,11 @@ void gprs_rlcmac_tbf::poll_timeout(struct gprs_rlcmac_pdch *pdch, uint32_t poll_
 		dl_tbf = tbf_as_dl_tbf(this);
 		/* POLL Timeout expecting DL ACK/NACK: implies direction == GPRS_RLCMAC_DL_TBF */
 		OSMO_ASSERT(dl_tbf);
-		if (!(dl_tbf->state_fsm.state_flags & (1 << GPRS_RLCMAC_FLAG_TO_DL_ACK))) {
+		if (!dl_tbf->m_last_dl_poll_ack_lost) {
 			LOGPTBF(this, LOGL_NOTICE,
 				"Timeout for polling PACKET DOWNLINK ACK: %s\n",
 				tbf_rlcmac_diag(dl_tbf));
-			dl_tbf->state_fsm.state_flags |= (1 << GPRS_RLCMAC_FLAG_TO_DL_ACK);
+			dl_tbf->m_last_dl_poll_ack_lost = true;
 		}
 		if (dl_tbf->state_is(TBF_ST_RELEASING))
 			bts_do_rate_ctr_inc(bts, CTR_RLC_REL_TIMEDOUT);
diff --git a/src/tbf.h b/src/tbf.h
index 37756b01..941e350a 100644
--- a/src/tbf.h
+++ b/src/tbf.h
@@ -110,8 +110,6 @@ enum tbf_counters { /* TBF counters from 3GPP TS 44.060 §13.4 */
 #define GPRS_RLCMAC_FLAG_CCCH		0 /* assignment on CCCH */
 #define GPRS_RLCMAC_FLAG_PACCH		1 /* assignment on PACCH */
 #define GPRS_RLCMAC_FLAG_DL_ACK		2 /* DL TBF: At least one DL ACK/NACK was recieved since it was assigned */
-#define GPRS_RLCMAC_FLAG_TO_DL_ACK	3 /* DL TBF: Failed to receive last polled DL ACK/NACK */
-
 #define TBF_TFI_UNSET 0xff
 
 #define T_START(tbf, t, T, r, f) tbf->t_start(t, T, r, f, __FILE__, __LINE__)
diff --git a/src/tbf_dl.cpp b/src/tbf_dl.cpp
index 3ffafbfe..170ed251 100644
--- a/src/tbf_dl.cpp
+++ b/src/tbf_dl.cpp
@@ -162,6 +162,7 @@ gprs_rlcmac_dl_tbf::gprs_rlcmac_dl_tbf(struct gprs_rlcmac_bts *bts_, GprsMs *ms)
 	m_tx_counter(0),
 	m_dl_ack_requested(false),
 	m_last_dl_poll_fn(-1),
+	m_last_dl_poll_ack_lost(false),
 	m_last_dl_drained_fn(-1),
 	m_dl_gprs_ctrs(NULL),
 	m_dl_egprs_ctrs(NULL)
@@ -858,7 +859,7 @@ struct msgb *gprs_rlcmac_dl_tbf::create_dl_acked_block(
 			LOGPTBFDL(this, LOGL_DEBUG,
 				  "Scheduling Ack/Nack polling, because it was requested explicitly "
 				  "(e.g. first final block sent).\n");
-		} else if (state_fsm.state_flags & (1 << GPRS_RLCMAC_FLAG_TO_DL_ACK)) {
+		} else if (m_last_dl_poll_ack_lost) {
 			LOGPTBFDL(this, LOGL_DEBUG,
 				  "Scheduling Ack/Nack polling, because polling timed out.\n");
 		} else {
@@ -879,10 +880,10 @@ struct msgb *gprs_rlcmac_dl_tbf::create_dl_acked_block(
 			if (is_final)
 				T_START(this, T3191, 3191, "final block (DL-TBF)", true);
 
-			state_fsm.state_flags &= ~(1 << GPRS_RLCMAC_FLAG_TO_DL_ACK); /* clear poll timeout flag */
-
 			/* Clear request flag */
 			m_dl_ack_requested = false;
+			/* clear poll timeout flag */
+			m_last_dl_poll_ack_lost = false;
 
 			/* set polling in header */
 			rlc.rrbp = rrbp;
@@ -1080,7 +1081,7 @@ int gprs_rlcmac_dl_tbf::rcvd_dl_ack(bool final_ack, unsigned first_bsn,
 	LOGPTBFDL(this, LOGL_DEBUG, "downlink acknowledge\n");
 
 	state_fsm.state_flags |= (1 << GPRS_RLCMAC_FLAG_DL_ACK);
-	state_fsm.state_flags &= ~(1 << GPRS_RLCMAC_FLAG_TO_DL_ACK);
+	m_last_dl_poll_ack_lost = false;
 
 	/* reset N3105 */
 	n_reset(N3105);
@@ -1118,7 +1119,7 @@ bool gprs_rlcmac_dl_tbf::need_poll_for_dl_ack_nack() const
 {
 	/* poll after POLL_ACK_AFTER_FRAMES frames, or when final block is tx or
 	 * when last polled DL ACK/NACK was lost. */
-	return state_fsm.state_flags & (1 << GPRS_RLCMAC_FLAG_TO_DL_ACK) ||
+	return m_last_dl_poll_ack_lost ||
 		m_tx_counter >= POLL_ACK_AFTER_FRAMES ||
 		m_dl_ack_requested;
 }
diff --git a/src/tbf_dl.h b/src/tbf_dl.h
index 6718c13b..ec75e327 100644
--- a/src/tbf_dl.h
+++ b/src/tbf_dl.h
@@ -71,6 +71,9 @@ struct gprs_rlcmac_dl_tbf : public gprs_rlcmac_tbf {
 	int32_t m_tx_counter; /* count all transmitted blocks */
 	bool m_dl_ack_requested;
 	int32_t m_last_dl_poll_fn;
+	/* Whether we failed to receive ("poll timeout") last PKT CTRL ACK from
+	 * MS polled during DL ACK/NACK with RRBP set in "m_last_dl_poll_fn": */
+	bool m_last_dl_poll_ack_lost;
 	int32_t m_last_dl_drained_fn;
 
 	struct BandWidth {