diff --git a/configure.ac b/configure.ac
index a016c99..0fa49f6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -389,6 +389,13 @@ AC_ARG_ENABLE(testing, AS_HELP_STRING([--enable-testing],
 					[enable_testing=${enableval}])
 AM_CONDITIONAL(TESTING, test "${enable_testing}" = "yes")
 
+if (test "${enable_testing}" = "yes"); then
+   AC_CHECK_DECLS([SOF_TIMESTAMPING_TX_COMPLETION, SCM_TSTAMP_COMPLETION],
+	[], [], [[#include <time.h>
+		#include <linux/errqueue.h>
+		#include <linux/net_tstamp.h>]])
+fi
+
 AC_ARG_ENABLE(experimental, AS_HELP_STRING([--enable-experimental],
 			[enable experimental tools]),
 					[enable_experimental=${enableval}])
diff --git a/tools/iso-tester.c b/tools/iso-tester.c
index c30c44c..b5e6388 100644
--- a/tools/iso-tester.c
+++ b/tools/iso-tester.c
@@ -1066,20 +1066,10 @@ static const struct iso_client_data connect_send_tx_timestamping = {
 	.send = &send_16_2_1,
 	.so_timestamping = (SOF_TIMESTAMPING_SOFTWARE |
 					SOF_TIMESTAMPING_OPT_ID |
-					SOF_TIMESTAMPING_TX_SOFTWARE),
-	.repeat_send = 1,
-	.repeat_send_pre_ts = 2,
-};
-
-static const struct iso_client_data connect_send_tx_sched_timestamping = {
-	.qos = QOS_16_2_1,
-	.expect_err = 0,
-	.send = &send_16_2_1,
-	.so_timestamping = (SOF_TIMESTAMPING_SOFTWARE |
 					SOF_TIMESTAMPING_TX_SOFTWARE |
-					SOF_TIMESTAMPING_OPT_TSONLY |
-					SOF_TIMESTAMPING_TX_SCHED),
+					SOF_TIMESTAMPING_TX_COMPLETION),
 	.repeat_send = 1,
+	.repeat_send_pre_ts = 2,
 };
 
 static const struct iso_client_data connect_send_tx_cmsg_timestamping = {
@@ -1087,7 +1077,8 @@ static const struct iso_client_data connect_send_tx_cmsg_timestamping = {
 	.expect_err = 0,
 	.send = &send_16_2_1,
 	.so_timestamping = (SOF_TIMESTAMPING_SOFTWARE |
-					SOF_TIMESTAMPING_TX_SOFTWARE),
+					SOF_TIMESTAMPING_OPT_TSONLY |
+					SOF_TIMESTAMPING_TX_COMPLETION),
 	.repeat_send = 1,
 	.cmsg_timestamping = true,
 };
@@ -1097,7 +1088,7 @@ static const struct iso_client_data connect_send_tx_no_poll_timestamping = {
 	.expect_err = 0,
 	.send = &send_16_2_1,
 	.so_timestamping = (SOF_TIMESTAMPING_SOFTWARE |
-					SOF_TIMESTAMPING_TX_SOFTWARE),
+					SOF_TIMESTAMPING_TX_COMPLETION),
 	.repeat_send = 1,
 	.no_poll_errqueue = true,
 };
@@ -2241,10 +2232,10 @@ static gboolean iso_recv_errqueue(GIOChannel *io, GIOCondition cond,
 	err = tx_tstamp_recv(&data->tx_ts, sk, isodata->send->iov_len);
 	if (err > 0)
 		return TRUE;
-	else if (!err && !data->step)
-		tester_test_passed();
-	else
+	else if (err)
 		tester_test_failed();
+	else if (!data->step)
+		tester_test_passed();
 
 	data->io_id[2] = 0;
 	return FALSE;
@@ -2289,7 +2280,7 @@ static void iso_tx_timestamping(struct test_data *data, GIOChannel *io)
 	int err;
 	unsigned int count;
 
-	if (!(isodata->so_timestamping & SOF_TIMESTAMPING_TX_RECORD_MASK))
+	if (!(isodata->so_timestamping & TS_TX_RECORD_MASK))
 		return;
 
 	tester_print("Enabling TX timestamping");
@@ -2336,7 +2327,7 @@ static void iso_tx_timestamping(struct test_data *data, GIOChannel *io)
 	}
 
 	if (isodata->cmsg_timestamping)
-		so &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
+		so &= ~TS_TX_RECORD_MASK;
 
 	err = setsockopt(sk, SOL_SOCKET, SO_TIMESTAMPING, &so, sizeof(so));
 	if (err < 0) {
@@ -2374,7 +2365,7 @@ static void iso_send_data(struct test_data *data, GIOChannel *io)
 		cmsg->cmsg_len = CMSG_LEN(sizeof(uint32_t));
 
 		*((uint32_t *)CMSG_DATA(cmsg)) = (isodata->so_timestamping &
-					SOF_TIMESTAMPING_TX_RECORD_MASK);
+					TS_TX_RECORD_MASK);
 	}
 
 	ret = sendmsg(sk, &msg, 0);
@@ -3645,11 +3636,6 @@ int main(int argc, char *argv[])
 	test_iso("ISO Send - TX Timestamping", &connect_send_tx_timestamping,
 						setup_powered, test_connect);
 
-	/* Test schedule-time TX timestamps are emitted */
-	test_iso("ISO Send - TX Sched Timestamping",
-			&connect_send_tx_sched_timestamping, setup_powered,
-			test_connect);
-
 	/* Test TX timestamping with flags set via per-packet CMSG */
 	test_iso("ISO Send - TX CMSG Timestamping",
 			&connect_send_tx_cmsg_timestamping, setup_powered,
diff --git a/tools/l2cap-tester.c b/tools/l2cap-tester.c
index 1780c9f..7f3be6c 100644
--- a/tools/l2cap-tester.c
+++ b/tools/l2cap-tester.c
@@ -381,7 +381,8 @@ static const struct l2cap_data client_connect_tx_timestamping_test = {
 	.data_len = sizeof(l2_data),
 	.so_timestamping = (SOF_TIMESTAMPING_SOFTWARE |
 					SOF_TIMESTAMPING_OPT_ID |
-					SOF_TIMESTAMPING_TX_SOFTWARE),
+					SOF_TIMESTAMPING_TX_SOFTWARE |
+					SOF_TIMESTAMPING_TX_COMPLETION),
 	.repeat_send = 2,
 };
 
@@ -594,7 +595,8 @@ static const struct l2cap_data le_client_connect_tx_timestamping_test = {
 	.data_len = sizeof(l2_data),
 	.so_timestamping = (SOF_TIMESTAMPING_SOFTWARE |
 					SOF_TIMESTAMPING_OPT_ID |
-					SOF_TIMESTAMPING_TX_SOFTWARE),
+					SOF_TIMESTAMPING_TX_SOFTWARE |
+					SOF_TIMESTAMPING_TX_COMPLETION),
 };
 
 static const struct l2cap_data le_client_connect_adv_success_test_1 = {
@@ -1345,10 +1347,10 @@ static gboolean recv_errqueue(GIOChannel *io, GIOCondition cond,
 	err = tx_tstamp_recv(&data->tx_ts, sk, l2data->data_len);
 	if (err > 0)
 		return TRUE;
-	else if (!err && !data->step)
-		tester_test_passed();
-	else
+	else if (err)
 		tester_test_failed();
+	else if (!data->step)
+		tester_test_passed();
 
 	data->err_io_id = 0;
 	return FALSE;
@@ -1362,7 +1364,7 @@ static void l2cap_tx_timestamping(struct test_data *data, GIOChannel *io)
 	int err;
 	unsigned int count;
 
-	if (!(l2data->so_timestamping & SOF_TIMESTAMPING_TX_RECORD_MASK))
+	if (!(l2data->so_timestamping & TS_TX_RECORD_MASK))
 		return;
 
 	sk = g_io_channel_unix_get_fd(io);
diff --git a/tools/sco-tester.c b/tools/sco-tester.c
index b88631d..7a4d684 100644
--- a/tools/sco-tester.c
+++ b/tools/sco-tester.c
@@ -319,6 +319,17 @@ static const struct sco_client_data connect_send_tx_timestamping = {
 	.send_data = data,
 	.so_timestamping = (SOF_TIMESTAMPING_SOFTWARE |
 					SOF_TIMESTAMPING_OPT_ID |
+					SOF_TIMESTAMPING_TX_SOFTWARE |
+					SOF_TIMESTAMPING_TX_COMPLETION),
+	.repeat_send = 2,
+};
+
+static const struct sco_client_data connect_send_no_flowctl_tx_timestamping = {
+	.expect_err = 0,
+	.data_len = sizeof(data),
+	.send_data = data,
+	.so_timestamping = (SOF_TIMESTAMPING_SOFTWARE |
+					SOF_TIMESTAMPING_OPT_ID |
 					SOF_TIMESTAMPING_TX_SOFTWARE),
 	.repeat_send = 2,
 };
@@ -738,10 +749,10 @@ static gboolean recv_errqueue(GIOChannel *io, GIOCondition cond,
 	err = tx_tstamp_recv(&data->tx_ts, sk, scodata->data_len);
 	if (err > 0)
 		return TRUE;
-	else if (!err && !data->step)
-		tester_test_passed();
-	else
+	else if (err)
 		tester_test_failed();
+	else if (!data->step)
+		tester_test_passed();
 
 	data->err_io_id = 0;
 	return FALSE;
@@ -755,7 +766,7 @@ static void sco_tx_timestamping(struct test_data *data, GIOChannel *io)
 	int err;
 	unsigned int count;
 
-	if (!(scodata->so_timestamping & SOF_TIMESTAMPING_TX_RECORD_MASK))
+	if (!(scodata->so_timestamping & TS_TX_RECORD_MASK))
 		return;
 
 	sk = g_io_channel_unix_get_fd(io);
@@ -1142,6 +1153,10 @@ int main(int argc, char *argv[])
 					&connect_send_tx_timestamping,
 					setup_powered, test_connect);
 
+	test_sco_no_flowctl("SCO CVSD Send No Flowctl - TX Timestamping",
+				&connect_send_no_flowctl_tx_timestamping,
+				setup_powered, test_connect);
+
 	test_sco_11("SCO CVSD 1.1 Send - Success", &connect_send_success,
 					setup_powered, test_connect);
 
diff --git a/tools/tester.h b/tools/tester.h
index b6de084..802c92e 100644
--- a/tools/tester.h
+++ b/tools/tester.h
@@ -20,6 +20,15 @@
 #define SEC_NSEC(_t)  ((_t) * 1000000000LL)
 #define TS_NSEC(_ts)  (SEC_NSEC((_ts)->tv_sec) + (_ts)->tv_nsec)
 
+#if !HAVE_DECL_SOF_TIMESTAMPING_TX_COMPLETION
+#define SOF_TIMESTAMPING_TX_COMPLETION	(1 << 18)
+#endif
+#if !HAVE_DECL_SCM_TSTAMP_COMPLETION
+#define SCM_TSTAMP_COMPLETION		(SCM_TSTAMP_ACK + 1)
+#endif
+#define TS_TX_RECORD_MASK		(SOF_TIMESTAMPING_TX_RECORD_MASK | \
+						SOF_TIMESTAMPING_TX_COMPLETION)
+
 struct tx_tstamp_data {
 	struct {
 		uint32_t id;
@@ -59,6 +68,13 @@ static inline int tx_tstamp_expect(struct tx_tstamp_data *data)
 		pos++;
 	}
 
+	if (data->so_timestamping & SOF_TIMESTAMPING_TX_COMPLETION) {
+		g_assert(pos < ARRAY_SIZE(data->expect));
+		data->expect[pos].type = SCM_TSTAMP_COMPLETION;
+		data->expect[pos].id = data->sent;
+		pos++;
+	}
+
 	data->sent++;
 
 	steps = pos - data->count;
@@ -77,6 +93,7 @@ static inline int tx_tstamp_recv(struct tx_tstamp_data *data, int sk, int len)
 	struct scm_timestamping *tss = NULL;
 	struct sock_extended_err *serr = NULL;
 	struct timespec now;
+	unsigned int i;
 
 	iov.iov_base = buf;
 	iov.iov_len = sizeof(buf);
@@ -89,7 +106,7 @@ static inline int tx_tstamp_recv(struct tx_tstamp_data *data, int sk, int len)
 
 	ret = recvmsg(sk, &msg, MSG_ERRQUEUE);
 	if (ret < 0) {
-		if (ret == EAGAIN || ret == EWOULDBLOCK)
+		if (errno == EAGAIN || errno == EWOULDBLOCK)
 			return data->count - data->pos;
 
 		tester_warn("Failed to read from errqueue: %s (%d)",
@@ -147,18 +164,29 @@ static inline int tx_tstamp_recv(struct tx_tstamp_data *data, int sk, int len)
 		return -EINVAL;
 	}
 
-	if ((data->so_timestamping & SOF_TIMESTAMPING_OPT_ID) &&
-				serr->ee_data != data->expect[data->pos].id) {
-		tester_warn("Bad timestamp id %u", serr->ee_data);
+	/* Find first unreceived timestamp of the right type */
+	for (i = 0; i < data->count; ++i) {
+		if (data->expect[i].type >= 0xffff)
+			continue;
+
+		if (serr->ee_info == data->expect[i].type) {
+			data->expect[i].type = 0xffff;
+			break;
+		}
+	}
+	if (i == data->count) {
+		tester_warn("Bad timestamp type %u", serr->ee_info);
 		return -EINVAL;
 	}
 
-	if (serr->ee_info != data->expect[data->pos].type) {
-		tester_warn("Bad timestamp type %u", serr->ee_info);
+	if ((data->so_timestamping & SOF_TIMESTAMPING_OPT_ID) &&
+				serr->ee_data != data->expect[i].id) {
+		tester_warn("Bad timestamp id %u", serr->ee_data);
 		return -EINVAL;
 	}
 
-	tester_print("Got valid TX timestamp %u", data->pos);
+	tester_print("Got valid TX timestamp %u (type %u, id %u)", i,
+						serr->ee_info, serr->ee_data);
 
 	++data->pos;