rlcmac: tbf_dl: Implement T3192

Related: OS#5500
Change-Id: I49c9068d1819d6189103908f6f92ce05952b74e6

5 files changed, 58 insertions, 6 deletions

diff --git a/include/osmocom/gprs/rlcmac/tbf_dl.h b/include/osmocom/gprs/rlcmac/tbf_dl.h
index 7fb3c9e..104b6e6 100644
--- a/include/osmocom/gprs/rlcmac/tbf_dl.h
+++ b/include/osmocom/gprs/rlcmac/tbf_dl.h
@@ -35,6 +35,7 @@ struct gprs_rlcmac_dl_tbf {
 	};
 
 	struct osmo_timer_list t3190;
+	struct osmo_timer_list t3192;
 };
 
 struct gprs_rlcmac_dl_tbf *gprs_rlcmac_dl_tbf_alloc(struct gprs_rlcmac_entity *gre);
diff --git a/src/rlcmac/rlcmac.c b/src/rlcmac/rlcmac.c
index f9281fb..f35c04d 100644
--- a/src/rlcmac/rlcmac.c
+++ b/src/rlcmac/rlcmac.c
@@ -50,6 +50,7 @@ static struct osmo_tdef T_defs_rlcmac[] = {
 	{ .T=3168, .default_val=5000,	.unit = OSMO_TDEF_MS,	.desc="Wait for PACKET UPLINK ASSIGNMENT (updated by BCCH SI13) (ms)" },
 	{ .T=3182, .default_val=5,	.unit = OSMO_TDEF_S,	.desc="Wait for Acknowledgement (s)" },
 	{ .T=3190, .default_val=5,	.unit = OSMO_TDEF_S,	.desc="Wait for Valid Downlink Data Received from the Network (s)" },
+	{ .T=3192, .default_val=0,	.unit = OSMO_TDEF_MS,	.desc="Wait for release of the TBF after reception of the final block (ms)" },
 	{ 0 } /* empty item at the end */
 };
 
@@ -571,9 +572,18 @@ int gprs_rlcmac_handle_ccch_pag_req2(const struct gsm48_paging2 *pag)
 	return rc;
 }
 
+/* Decode T3192. 3GPP TS 44.060 Table 12.24.2: GPRS Cell Options information element details */
+static unsigned int gprs_rlcmac_decode_t3192(unsigned int t3192_encoded)
+{
+	static const unsigned int decode_t3192_tbl[8] = {500, 1000, 1500, 0, 80, 120, 160, 200};
+	OSMO_ASSERT(t3192_encoded <= 7);
+	return decode_t3192_tbl[t3192_encoded];
+}
+
 int gprs_rlcmac_handle_bcch_si13(const struct gsm48_system_information_type_13 *si13)
 {
 	int rc;
+	unsigned int t3192;
 
 	LOGRLCMAC(LOGL_DEBUG, "Rx SI13 from lower layers\n");
 	memcpy(g_rlcmac_ctx->si13, si13, GSM_MACBLOCK_LEN);
@@ -594,9 +604,9 @@ int gprs_rlcmac_handle_bcch_si13(const struct gsm48_system_information_type_13 *
 		      (g_rlcmac_ctx->si13ro.u.PBCCH_Not_present.GPRS_Cell_Options.T3168 + 1) * 500,
 		      OSMO_TDEF_MS);
 
-	/* TODO: Update tdef for T3192 as per TS 44.060 Table 12.24.2
-	 * osmo_tdef_set(g_rlcmac_ctx->T_defs, 3192, si13ro.u.PBCCH_Not_present.GPRS_Cell_Options.T3192, enum osmo_tdef_unit val_unit);
-	 */
+	/* Update tdef for T3192 as per TS 44.060 Table 12.24.2 */
+	t3192 = gprs_rlcmac_decode_t3192(g_rlcmac_ctx->si13ro.u.PBCCH_Not_present.GPRS_Cell_Options.T3192);
+	osmo_tdef_set(g_rlcmac_ctx->T_defs, 3192, t3192, OSMO_TDEF_MS);
 
 	return rc;
 }
@@ -674,6 +684,16 @@ static int gprs_rlcmac_handle_pkt_dl_ass(const struct osmo_gprs_rlcmac_prim *rlc
 					     GPRS_RLCMAC_PDCH_ULC_POLL_DL_ASS,
 					     gre);
 	}
+
+	/* 9.3.2.6 Release of downlink Temporary Block Flow:
+	 * If the MS, [...] receives a PACKET DOWNLINK ASSIGNMENT with the Control Ack bit
+	 * set to '1' [...] while its timer T3192 is running, the MS shall stop timer T3192,
+	 * consider this downlink TBF released and act upon the new assignments.
+	 */
+	if (dlass->CONTROL_ACK && gre->dl_tbf) {
+		if (osmo_timer_pending(&gre->dl_tbf->t3192))
+			gprs_rlcmac_dl_tbf_free(gre->dl_tbf);
+	}
 	return rc;
 }
 
diff --git a/src/rlcmac/tbf_dl.c b/src/rlcmac/tbf_dl.c
index c6205c3..a7f0ea9 100644
--- a/src/rlcmac/tbf_dl.c
+++ b/src/rlcmac/tbf_dl.c
@@ -28,6 +28,7 @@
 #include <osmocom/gprs/rlcmac/pdch_ul_controller.h>
 
 static void gprs_rlcmac_dl_tbf_t3190_timer_cb(void *data);
+static void gprs_rlcmac_dl_tbf_t3192_timer_cb(void *data);
 
 struct gprs_rlcmac_dl_tbf *gprs_rlcmac_dl_tbf_alloc(struct gprs_rlcmac_entity *gre)
 {
@@ -54,6 +55,7 @@ struct gprs_rlcmac_dl_tbf *gprs_rlcmac_dl_tbf_alloc(struct gprs_rlcmac_entity *g
 	OSMO_ASSERT(dl_tbf->blkst);
 
 	osmo_timer_setup(&dl_tbf->t3190, gprs_rlcmac_dl_tbf_t3190_timer_cb, dl_tbf);
+	osmo_timer_setup(&dl_tbf->t3192, gprs_rlcmac_dl_tbf_t3192_timer_cb, dl_tbf);
 
 	return dl_tbf;
 
@@ -75,6 +77,7 @@ void gprs_rlcmac_dl_tbf_free(struct gprs_rlcmac_dl_tbf *dl_tbf)
 	gre = tbf->gre;
 
 	osmo_timer_del(&dl_tbf->t3190);
+	osmo_timer_del(&dl_tbf->t3192);
 
 	msgb_free(dl_tbf->llc_rx_msg);
 	dl_tbf->llc_rx_msg = NULL;
@@ -109,6 +112,29 @@ void gprs_rlcmac_dl_tbf_t3190_start(struct gprs_rlcmac_dl_tbf *dl_tbf)
 	osmo_timer_schedule(&dl_tbf->t3190, val_sec, 0);
 }
 
+/* This timer is used on the mobile station side when the mobile station has
+ * received all of the RLC data blocks. When timer T3192 expires the mobile station
+ * shall release the resources associated with the TBF (e.g. TFI) and begin to
+ * monitor its paging channel. */
+static void gprs_rlcmac_dl_tbf_t3192_timer_cb(void *data)
+{
+	struct gprs_rlcmac_dl_tbf *dl_tbf = data;
+
+	LOGPTBFDL(dl_tbf, LOGL_INFO, "Timeout of T3192\n");
+
+	gprs_rlcmac_dl_tbf_free(dl_tbf);
+}
+
+void gprs_rlcmac_dl_tbf_t3192_start(struct gprs_rlcmac_dl_tbf *dl_tbf)
+{
+	unsigned long val_msec;
+	val_msec = osmo_tdef_get(g_rlcmac_ctx->T_defs, 3192, OSMO_TDEF_MS, -1);
+
+	LOGPTBFDL(dl_tbf, LOGL_INFO, "Starting T3192 (%lu ms)\n", val_msec);
+	OSMO_ASSERT(gprs_rlcmac_tbf_dl_state(dl_tbf) == GPRS_RLCMAC_TBF_DL_ST_FINISHED);
+	osmo_timer_schedule(&dl_tbf->t3192, val_msec / 1000, (val_msec % 1000) * 1000);
+}
+
 static uint8_t dl_tbf_dl_slotmask(struct gprs_rlcmac_dl_tbf *dl_tbf)
 {
 	uint8_t dl_slotmask = 0;
@@ -161,10 +187,11 @@ struct msgb *gprs_rlcmac_dl_tbf_create_pkt_dl_ack_nack(struct gprs_rlcmac_dl_tbf
 		goto free_ret;
 	}
 
-	/* Stop T3190 if transmitting final Downlink Ack/Nack */
-	if (gprs_rlcmac_tbf_dl_state(dl_tbf) == GPRS_RLCMAC_TBF_DL_ST_FINISHED)
+	/* Transmitting final Downlink Ack/Nack: Stop T3190 (if still armed), re-arm T3192 */
+	if (gprs_rlcmac_tbf_dl_state(dl_tbf) == GPRS_RLCMAC_TBF_DL_ST_FINISHED) {
 		osmo_timer_del(&dl_tbf->t3190);
-
+		gprs_rlcmac_dl_tbf_t3192_start(dl_tbf);
+	}
 	return msg;
 
 free_ret:
diff --git a/src/rlcmac/tbf_dl_fsm.c b/src/rlcmac/tbf_dl_fsm.c
index 342256f..158b802 100644
--- a/src/rlcmac/tbf_dl_fsm.c
+++ b/src/rlcmac/tbf_dl_fsm.c
@@ -80,6 +80,8 @@ static void st_flow(struct osmo_fsm_inst *fi, uint32_t event, void *data)
 
 static void st_finished(struct osmo_fsm_inst *fi, uint32_t event, void *data)
 {
+	/* Wait to be freed by T3190/T3192. */
+
 	//struct gprs_rlcmac_tbf_dl_fsm_ctx *ctx = (struct gprs_rlcmac_tbf_dl_fsm_ctx *)fi->priv;
 	switch (event) {
 	case GPRS_RLCMAC_TBF_DL_EV_LAST_DL_DATA_RECVD:
diff --git a/tests/rlcmac/rlcmac_prim_test.err b/tests/rlcmac/rlcmac_prim_test.err
index 087e371..c6a7a73 100644
--- a/tests/rlcmac/rlcmac_prim_test.err
+++ b/tests/rlcmac/rlcmac_prim_test.err
@@ -911,6 +911,7 @@ DLGLOBAL DEBUG Register POLL (TS=7 FN=21, reason=DL_ACK)
 DLGLOBAL DEBUG Rx from lower layers: L1CTL-PDCH_RTS.indication
 DLGLOBAL DEBUG (ts=7,fn=21,usf=0) Tx DL ACK/NACK FinalAck=1
 DLGLOBAL DEBUG TBF(DL:NR-0:TLLI-00000001) - V(N): "IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIR" R=Received I=Invalid
+DLGLOBAL INFO TBF(DL:NR-0:TLLI-00000001) Starting T3192 (0 ms)
 DLGLOBAL DEBUG Tx to lower layers: L1CTL-PDCH_DATA.request
 DLGLOBAL INFO DL_TBF_ASS{IDLE}: Deallocated
 DLGLOBAL INFO DL_TBF{FINISHED}: Deallocated
@@ -955,6 +956,7 @@ DLGLOBAL INFO UL_TBF_ASS{IDLE}: Received Event START_FROM_DL_TBF
 DLGLOBAL INFO UL_TBF{NEW}: Received Event UL_ASS_START
 DLGLOBAL INFO UL_TBF{NEW}: state_chg to ASSIGN
 DLGLOBAL INFO UL_TBF_ASS{IDLE}: state_chg to WAIT_PKT_UL_ASS
+DLGLOBAL INFO TBF(DL:NR-0:TLLI-00000001) Starting T3192 (0 ms)
 DLGLOBAL DEBUG Tx to lower layers: L1CTL-PDCH_DATA.request
 DLGLOBAL DEBUG Rx from lower layers: L1CTL-PDCH_DATA.indication
 DLGLOBAL INFO TS=7 FN=26 Rx Pkt UL ASS