lms: Drop rx_underruns rate ctr, add tx_drop_* rate ctr

After discussion in [1] and further look at the code, it became obvios
rx_underrun events are not happening in general for any SDR (don't
exist), so let's drop that counter. Instead, add Tx Dropped Packet counters,
which were not accounted prior to this commit.

[1] https://github.com/osmocom/osmo-trx/commit/bde55afd29fc9aae10eb11f6515821afa39b772d

Change-Id: Iff1535c219a4695a511d383d7c4b06ef6eff959d

2 files changed, 61 insertions, 28 deletions

diff --git a/Transceiver52M/device/lms/LMSDevice.cpp b/Transceiver52M/device/lms/LMSDevice.cpp
index 0eaf0a3..f55b555 100644
--- a/Transceiver52M/device/lms/LMSDevice.cpp
+++ b/Transceiver52M/device/lms/LMSDevice.cpp
@@ -574,38 +574,37 @@ GSM::Time LMSDevice::minLatency() {
 	/* UNUSED on limesdr (only used on usrp1/2) */
 	return GSM::Time(0,0);
 }
-
-void LMSDevice::update_stream_stats(size_t chan, bool * underrun, bool * overrun)
+/*!
+ * Issue tracking description of several events: https://github.com/myriadrf/LimeSuite/issues/265
+ */
+void LMSDevice::update_stream_stats_rx(size_t chan, bool *overrun)
 {
 	lms_stream_status_t status;
 	bool changed = false;
 
 	if (LMS_GetStreamStatus(&m_lms_stream_rx[chan], &status) != 0) {
-		LOGCHAN(chan, DDEV, ERROR) << "LMS_GetStreamStatus failed";
+		LOGCHAN(chan, DDEV, ERROR) << "Rx LMS_GetStreamStatus failed";
 		return;
 	}
 
-	if (status.underrun) {
-		changed = true;
-		*underrun = true;
-		LOGCHAN(chan, DDEV, ERROR) << "recv Underrun! ("
-					   << m_ctr[chan].rx_underruns << " -> "
-					   << status.underrun << ")";
-	}
-	m_ctr[chan].rx_underruns += status.underrun;
-
+	/* FIFO overrun is counted when Rx FIFO is full but new data comes from
+	   the board and oldest samples in FIFO are overwritte. Value count
+	   since the last call to LMS_GetStreamStatus(stream). */
 	if (status.overrun) {
 		changed = true;
 		*overrun = true;
-		LOGCHAN(chan, DDEV, ERROR) << "recv Overrun! ("
+		LOGCHAN(chan, DDEV, ERROR) << "Rx Overrun! ("
 					   << m_ctr[chan].rx_overruns << " -> "
 					   << status.overrun << ")";
 	}
 	m_ctr[chan].rx_overruns += status.overrun;
 
+	/* Dropped packets in Rx are counted when gaps in Rx timestamps are
+	   detected (likely because buffer oveflow in hardware). Value count
+	   since the last call to LMS_GetStreamStatus(stream). */
 	if (status.droppedPackets) {
 		changed = true;
-		LOGCHAN(chan, DDEV, ERROR) << "recv Dropped packets by HW! ("
+		LOGCHAN(chan, DDEV, ERROR) << "Rx Dropped packets by HW! ("
 					   << m_ctr[chan].rx_dropped_samples << " -> "
 					   << m_ctr[chan].rx_dropped_samples +
 					      status.droppedPackets
@@ -653,7 +652,7 @@ int LMSDevice::readSamples(std::vector < short *>&bufs, int len, bool * overrun,
 		while ((avail_smpls = rx_buffers[i]->avail_smpls(timestamp)) < len) {
 			thread_enable_cancel(false);
 			num_smpls = LMS_RecvStream(&m_lms_stream_rx[i], bufs[i], len - avail_smpls, &rx_metadata, 100);
-			update_stream_stats(i, underrun, overrun);
+			update_stream_stats_rx(i, overrun);
 			thread_enable_cancel(true);
 			if (num_smpls <= 0) {
 				LOGCHAN(i, DDEV, ERROR) << "Device receive timed out (" << rc << " vs exp " << len << ").";
@@ -697,13 +696,53 @@ int LMSDevice::readSamples(std::vector < short *>&bufs, int len, bool * overrun,
 	return len;
 }
 
+void LMSDevice::update_stream_stats_tx(size_t chan, bool *underrun)
+{
+	lms_stream_status_t status;
+	bool changed = false;
+
+	if (LMS_GetStreamStatus(&m_lms_stream_tx[chan], &status) != 0) {
+		LOGCHAN(chan, DDEV, ERROR) << "Tx LMS_GetStreamStatus failed";
+		return;
+	}
+
+	/* FIFO underrun is counted when Tx is running but FIFO is empty for
+	   >100 ms (500ms in older versions). Value count since the last call to
+	   LMS_GetStreamStatus(stream). */
+	if (status.underrun) {
+		changed = true;
+		*underrun = true;
+		LOGCHAN(chan, DDEV, ERROR) << "Tx Underrun! ("
+					   << m_ctr[chan].tx_underruns << " -> "
+					   << status.underrun << ")";
+	}
+	m_ctr[chan].tx_underruns += status.underrun;
+
+	/* Dropped packets in Tx are counted only when timestamps are enabled
+	   and SDR drops packet because of late timestamp. Value count since the
+	   last call to LMS_GetStreamStatus(stream). */
+	if (status.droppedPackets) {
+		changed = true;
+		LOGCHAN(chan, DDEV, ERROR) << "Tx Dropped packets by HW! ("
+					   << m_ctr[chan].tx_dropped_samples << " -> "
+					   << m_ctr[chan].tx_dropped_samples +
+					      status.droppedPackets
+					   << ")";
+		m_ctr[chan].tx_dropped_events++;
+	}
+	m_ctr[chan].tx_dropped_samples += status.droppedPackets;
+
+	if (changed)
+		osmo_signal_dispatch(SS_DEVICE, S_DEVICE_COUNTER_CHANGE, &m_ctr[chan]);
+
+}
+
 int LMSDevice::writeSamples(std::vector < short *>&bufs, int len,
 			    bool * underrun, unsigned long long timestamp,
 			    bool isControl)
 {
 	int rc = 0;
 	unsigned int i;
-	lms_stream_status_t status;
 	lms_stream_meta_t tx_metadata = {};
 	tx_metadata.flushPartialPacket = false;
 	tx_metadata.waitForTimestamp = true;
@@ -725,19 +764,12 @@ int LMSDevice::writeSamples(std::vector < short *>&bufs, int len,
 		LOGCHAN(i, DDEV, DEBUG) << "send buffer of len " << len << " timestamp " << std::hex << tx_metadata.timestamp;
 		thread_enable_cancel(false);
 		rc = LMS_SendStream(&m_lms_stream_tx[i], bufs[i], len, &tx_metadata, 100);
+		update_stream_stats_tx(i, underrun);
+		thread_enable_cancel(true);
 		if (rc != len) {
-			LOGCHAN(i, DDEV, ERROR) << "LMS: Device send timed out";
+			LOGCHAN(i, DDEV, ERROR) << "LMS: Device Tx timed out (" << rc << " vs exp " << len << ").";
+			return -1;
 		}
-
-		if (LMS_GetStreamStatus(&m_lms_stream_tx[i], &status) == 0) {
-			if (status.underrun > m_ctr[i].tx_underruns) {
-				*underrun = true;
-				m_ctr[i].tx_underruns = status.underrun;
-				osmo_signal_dispatch(SS_DEVICE, S_DEVICE_COUNTER_CHANGE, &m_ctr[i]);
-			}
-
-		}
-		thread_enable_cancel(true);
 	}
 
 	return rc;
diff --git a/Transceiver52M/device/lms/LMSDevice.h b/Transceiver52M/device/lms/LMSDevice.h
index 906fbee..bc79f97 100644
--- a/Transceiver52M/device/lms/LMSDevice.h
+++ b/Transceiver52M/device/lms/LMSDevice.h
@@ -65,7 +65,8 @@ private:
 	bool do_filters(size_t chan);
 	int get_ant_idx(const std::string & name, bool dir_tx, size_t chan);
 	bool flush_recv(size_t num_pkts);
-	void update_stream_stats(size_t chan, bool * underrun, bool * overrun);
+	void update_stream_stats_rx(size_t chan, bool *overrun);
+	void update_stream_stats_tx(size_t chan, bool *underrun);
 
 public: