From eb12a3dfcab4563e0057c9c86498fc2481cbd810 Mon Sep 17 00:00:00 2001
From: Pauli Virtanen <pav@iki.fi>
Date: Wed, 15 Mar 2023 23:34:12 +0200
Subject: [PATCH] bluez5: acquire all BAP transports in a CIG at the same time

We need to acquire and release all transports in the same CIG at the
same time.

Due to current kernel ISO socket limitations, this cannot be done one by
one.
---
 spa/plugins/bluez5/bluez5-dbus.c | 103 +++++++++++++++++++++++++++++--
 1 file changed, 99 insertions(+), 4 deletions(-)

diff --git a/spa/plugins/bluez5/bluez5-dbus.c b/spa/plugins/bluez5/bluez5-dbus.c
index 6ca480949..fe2a87a51 100644
--- a/spa/plugins/bluez5/bluez5-dbus.c
+++ b/spa/plugins/bluez5/bluez5-dbus.c
@@ -2999,9 +2999,8 @@ finish:
 	}
 }
 
-static int transport_acquire(void *data, bool optional)
+static int do_transport_acquire(struct spa_bt_transport *transport)
 {
-	struct spa_bt_transport *transport = data;
 	struct spa_bt_monitor *monitor = transport->monitor;
 	DBusMessage *m;
 	DBusError err;
@@ -3045,6 +3044,65 @@ static int transport_acquire(void *data, bool optional)
 	return 0;
 }
 
+static bool transport_in_same_cig(struct spa_bt_transport *transport, struct spa_bt_transport *other)
+{
+	return (other->profile & (SPA_BT_PROFILE_BAP_SINK | SPA_BT_PROFILE_BAP_SOURCE)) &&
+		other->bap_cig == transport->bap_cig &&
+		other->bap_initiator;
+}
+
+static bool another_cig_transport_active(struct spa_bt_transport *transport)
+{
+	struct spa_bt_monitor *monitor = transport->monitor;
+	struct spa_bt_transport *t;
+
+	spa_list_for_each(t, &monitor->transport_list, link) {
+		if (!transport_in_same_cig(transport, t) || t == transport)
+			continue;
+		if (t->acquired)
+			return true;
+	}
+
+	return false;
+}
+
+static int transport_acquire(void *data, bool optional)
+{
+	struct spa_bt_transport *transport = data;
+	struct spa_bt_monitor *monitor = transport->monitor;
+
+	/*
+	 * XXX: When as BAP Central, all CIS in a CIG must be acquired at the same time.
+	 * XXX: This is because of kernel ISO socket limitations, which does not handle
+	 * XXX: currently starting streams in the group one by one.
+	 */
+	if (transport->bap_initiator && !another_cig_transport_active(transport)) {
+		struct spa_bt_transport *t;
+
+		spa_list_for_each(t, &monitor->transport_list, link) {
+			if (!transport_in_same_cig(transport, t) || t == transport)
+				continue;
+
+			spa_log_debug(monitor->log, "Acquire CIG %d: transport %s",
+					transport->bap_cig, t->path);
+
+			do_transport_acquire(t);
+		}
+
+		spa_log_debug(monitor->log, "Acquire CIG %d: transport %s",
+				transport->bap_cig, transport->path);
+	}
+	if (transport->bap_initiator &&
+			(transport->fd >= 0 || transport->acquire_call)) {
+		/* Already acquired/acquiring */
+		spa_log_debug(monitor->log, "Acquiring %s: was in acquired CIG", transport->path);
+		spa_bt_transport_emit_state_changed(transport, transport->state, transport->state);
+		return 0;
+	}
+
+	return do_transport_acquire(data);
+}
+
 static void transport_release_reply(DBusPendingCall *pending, void *user_data)
 {
 	struct spa_bt_transport *transport = user_data;
@@ -3085,9 +3143,8 @@ static void transport_release_reply(DBusPendingCall *pending, void *user_data)
 	dbus_message_unref(r);
 }
 
-static int transport_release(void *data)
+static int do_transport_release(struct spa_bt_transport *transport)
 {
-	struct spa_bt_transport *transport = data;
 	struct spa_bt_monitor *monitor = transport->monitor;
 	DBusMessage *m;
 	struct spa_bt_transport *t_linked;
@@ -3147,6 +3204,44 @@ static int transport_release(void *data)
 	return 0;
 }
 
+static int transport_release(void *data)
+{
+	struct spa_bt_transport *transport = data;
+	struct spa_bt_monitor *monitor = transport->monitor;
+	struct spa_bt_transport *t;
+
+	/*
+	 * XXX: When as BAP Central, release CIS in a CIG when the last transport
+	 * XXX: goes away.
+	 */
+	if (transport->bap_initiator) {
+		/* Check if another transport is alive */
+		if (another_cig_transport_active(transport)) {
+			spa_log_debug(monitor->log, "Releasing %s: wait for CIG %d",
+					transport->path, transport->bap_cig);
+			return 0;
+		}
+
+		/* Release remaining transports in CIG */
+		spa_list_for_each(t, &monitor->transport_list, link) {
+			if (!transport_in_same_cig(transport, t) || t == transport)
+				continue;
+
+			spa_log_debug(monitor->log, "Release CIG %d: transport %s",
+					transport->bap_cig, t->path);
+
+			if (t->fd >= 0)
+				do_transport_release(t);
+		}
+
+		spa_log_debug(monitor->log, "Release CIG %d: transport %s",
+				transport->bap_cig, transport->path);
+	}
+
+	return do_transport_release(data);
+}
+
+
 static const struct spa_bt_transport_implementation transport_impl = {
 	SPA_VERSION_BT_TRANSPORT_IMPLEMENTATION,
 	.acquire = transport_acquire,