3 is the latest approved patch-set.
No files were changed between the latest approved patch-set and the submitted one.


trxcon/trx_if: negotiate TRXD PDU version 1 (TRXDv1)

Now that trx_if.c is built against libosmo-trx, enable TRXDv1 by
negotiating it (SETFORMAT) before every POWERON, since the transceiver
may reset its active format back to legacy on the preceding POWEROFF.

This significantly improves the ttcn3-bts-test pass/fail ratio in the
frequency hopping configuration: TRXDv1 lets the transceiver
(osmo-trx-proxy) send us NOPE.ind, which we rely on to keep driving
uplink bursts even when no downlink burst was received.

Change-Id: I08d588f74925bb7a85e131defc0fa82158d90680
Related: OS#6638
---
M src/host/trxcon/src/trx_if.c
M src/host/trxcon/src/trxcon_shim.c
2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/src/host/trxcon/src/trx_if.c b/src/host/trxcon/src/trx_if.c
index a974b46..bbbc93f 100644
--- a/src/host/trxcon/src/trx_if.c
+++ b/src/host/trxcon/src/trx_if.c
@@ -45,6 +45,13 @@
 #include <osmocom/bb/trxcon/trx_if.h>
 #include <osmocom/bb/trxcon/logging.h>
 
+/* Highest TRXD PDU version supported by trxcon (TRXDv1).
+ *
+ * TRXDv2 requires Tx PDUs to contain modulation and training sequence info.
+ * struct trxcon_phyif_burst_req currently does not contain this information,
+ * so we cannot populate the necessary fields in trx_if_handle_phyif_burst_req(). */
+#define TRXD_PDU_VER_MAX	1
+
 /* Give up after 3 retransmissions of a TRXC command */
 #define TRX_MAX_RETRANS		3
 
@@ -148,6 +155,15 @@
 	return osmo_trxc_client_poweron(trx->trxc_client, &trx_poweron_rsp_cb, trx);
 }
 
+static void trx_setformat_cb(struct osmo_trxc_client *client,
+			     uint8_t ver_use, void *cb_data)
+{
+	struct trx_instance *trx = cb_data;
+
+	LOGPFSML(trx->fi, LOGL_INFO, "Using TRXD PDU version %u\n", ver_use);
+	osmo_trx_ep_set_pdu_ver(trx->ep, 0, ver_use);
+}
+
 static int trx_if_cmd_setslot(struct trx_instance *trx,
 			      const struct trxcon_phyif_cmdp_setslot *cmdp)
 {
@@ -400,8 +416,11 @@
 	}
 }
 
-/* No state change here: the POWERON response (see trx_poweron_rsp_cb())
- * is what moves us to TRX_ST_POWERON. */
+/* (Re-)negotiate the TRXD PDU format and send POWERON right behind it,
+ * since the transceiver may have reset its active format back to legacy
+ * on the preceding POWEROFF (or never negotiated it at all, if this is the
+ * very first POWERON). No state change here: the POWERON response (see
+ * trx_poweron_rsp_cb()) is what moves us to TRX_ST_POWERON. */
 static void trx_fsm_handle_poweron_req(struct osmo_fsm_inst *fi)
 {
 	struct trx_instance *trx = fi->priv;
@@ -411,6 +430,9 @@
 		return;
 	}
 
+	osmo_trxc_client_negotiate_format(trx->trxc_client,
+					  TRXD_PDU_VER_MAX,
+					  &trx_setformat_cb, trx);
 	trx_if_cmd_poweron(trx);
 }
 
@@ -488,8 +510,8 @@
 		.tn = bi->tn,
 		.toa256 = bi->toa256,
 		.rssi = bi->rssi,
-		.burst = &bi->burst[0],
-		.burst_len = bi->burst_len,
+		.burst = (bi->flags & OSMO_TRXD_F_NOPE_IND) ? NULL : &bi->burst[0],
+		.burst_len = (bi->flags & OSMO_TRXD_F_NOPE_IND) ? 0 : bi->burst_len,
 	};
 
 	trxcon_phyif_handle_burst_ind(trx->priv, &phybi);
diff --git a/src/host/trxcon/src/trxcon_shim.c b/src/host/trxcon/src/trxcon_shim.c
index ed2d402..3446f13 100644
--- a/src/host/trxcon/src/trxcon_shim.c
+++ b/src/host/trxcon/src/trxcon_shim.c
@@ -232,8 +232,16 @@
 		.burst_len = phybi->burst_len,
 	};
 
-	OSMO_ASSERT(phybi->burst_len <= sizeof(bi.burst));
-	memcpy(&bi.burst[0], phybi->burst, phybi->burst_len);
+	if (phybi->burst_len > 0) {
+		OSMO_ASSERT(phybi->burst_len <= sizeof(bi.burst));
+		memcpy(bi.burst, phybi->burst, phybi->burst_len);
+	} else {
+		/* NOPE.ind: the transceiver did not detect a burst for this fn/tn,
+		 * but still reports timing/level measurements.  Feed the scheduler
+		 * with a burst all soft-bits of which are uncertain (50% 0, 50% 1). */
+		bi.burst_len = GSM_NBITS_NB_GMSK_BURST;
+		memset(bi.burst, 0, bi.burst_len);
+	}
 
 	/* Poke scheduler */
 	return l1sched_handle_rx_burst(trxcon->sched, &bi);

