From 9165291c43cb0d8d8c06139068860e7080a1b454 Mon Sep 17 00:00:00 2001
From: Pauli Virtanen <pav@iki.fi>
Date: Sat, 2 Mar 2024 00:37:02 +0200
Subject: [PATCH] bluez5: iso-io: drop RX data when source is not running

When media-source is not running, we need to drop any RX data so that
there is room in the socket buffer for the latency reporting.
---
 spa/plugins/bluez5/iso-io.c       | 21 +++++++++++++++++++--
 spa/plugins/bluez5/media-source.c | 27 ++++++++++++++++++++++++++-
 2 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/spa/plugins/bluez5/iso-io.c b/spa/plugins/bluez5/iso-io.c
index 6b1e7378f..de7a8565a 100644
--- a/spa/plugins/bluez5/iso-io.c
+++ b/spa/plugins/bluez5/iso-io.c
@@ -145,6 +145,15 @@ static int set_timers(struct group *group)
 	return set_timeout(group, group->next);
 }
 
+static void drop_rx(int fd)
+{
+	ssize_t res;
+
+	do {
+		res = recv(fd, NULL, 0, MSG_TRUNC | MSG_DONTWAIT);
+	} while (res >= 0);
+}
+
 static void group_on_timeout(struct spa_source *source)
 {
 	struct group *group = source->data;
@@ -166,8 +175,13 @@ static void group_on_timeout(struct spa_source *source)
 	 * desynchronization.
 	 */
 	spa_list_for_each(stream, &group->streams, link) {
-		if (!stream->sink)
+		if (!stream->sink) {
+			if (!stream->pull) {
+				/* Source not running: drop any incoming data */
+				drop_rx(stream->fd);
+			}
 			continue;
+		}
 
 		if (stream->this.need_resync) {
 			resync = true;
@@ -453,9 +467,12 @@ static bool group_is_enabled(struct group *group)
 {
 	struct stream *stream;
 
-	spa_list_for_each(stream, &group->streams, link)
+	spa_list_for_each(stream, &group->streams, link) {
+		if (!stream->sink)
+			continue;
 		if (stream->pull)
 			return true;
+	}
 
 	return false;
 }
diff --git a/spa/plugins/bluez5/media-source.c b/spa/plugins/bluez5/media-source.c
index f92202634..c5e6753fc 100644
--- a/spa/plugins/bluez5/media-source.c
+++ b/spa/plugins/bluez5/media-source.c
@@ -35,6 +35,7 @@
 #include "defs.h"
 #include "rtp.h"
 #include "media-codecs.h"
+#include "iso-io.h"
 
 SPA_LOG_TOPIC_DEFINE_STATIC(log_topic, "spa.bluez5.source.media");
 #undef SPA_LOG_TOPIC_DEFAULT
@@ -526,6 +527,8 @@ static void media_on_ready_read(struct spa_source *source)
 stop:
 	if (this->source.loop)
 		spa_loop_remove_source(this->data_loop, &this->source);
+	if (this->transport && this->transport->iso_io)
+		spa_bt_iso_io_set_cb(this->transport->iso_io, NULL, NULL);
 }
 
 static int setup_matching(struct impl *this)
@@ -612,6 +615,21 @@ static void media_on_timeout(struct spa_source *source)
 	set_timeout(this, this->next_time);
 }
 
+static void media_iso_pull(struct spa_bt_iso_io *iso_io)
+{
+	/* TODO: eventually use iso-io here, currently this is used just to indicate to
+	 * iso-io whether this source is running or not. */
+}
+
+static int do_start_iso_io(struct spa_loop *loop, bool async, uint32_t seq,
+		const void *data, size_t size, void *user_data)
+{
+	struct impl *this = user_data;
+
+	spa_bt_iso_io_set_cb(this->transport->iso_io, media_iso_pull, this);
+	return 0;
+}
+
 static int transport_start(struct impl *this)
 {
 	int res, val;
@@ -669,6 +687,8 @@ static int transport_start(struct impl *this)
 				port->current_format.info.raw.rate * 80 / 1000);
 	}
 
+	this->sample_count = 0;
+
 	this->source.data = this;
 
 	this->source.fd = this->fd;
@@ -679,7 +699,8 @@ static int transport_start(struct impl *this)
 		spa_log_error(this->log, "%p: failed to add poll source: %s", this,
 				spa_strerror(res));
 
-	this->sample_count = 0;
+	if (this->transport->iso_io)
+		spa_loop_invoke(this->data_loop, do_start_iso_io, 0, NULL, 0, true, this);
 
 	this->transport_started = true;
 
@@ -737,6 +758,8 @@ static int do_remove_source(struct spa_loop *loop,
 
 	if (this->timer_source.loop)
 		spa_loop_remove_source(this->data_loop, &this->timer_source);
+	if (this->transport && this->transport->iso_io)
+		spa_bt_iso_io_set_cb(this->transport->iso_io, NULL, NULL);
 	set_timeout(this, 0);
 
 	return 0;
@@ -757,6 +780,8 @@ static int do_remove_transport_source(struct spa_loop *loop,
 
 	if (this->source.loop)
 		spa_loop_remove_source(this->data_loop, &this->source);
+	if (this->transport->iso_io)
+		spa_bt_iso_io_set_cb(this->transport->iso_io, NULL, NULL);
 
 	return 0;
 }