From 0dde4f8774af4f9e5236c87276d5413d6f4910eb Mon Sep 17 00:00:00 2001
From: Huang-Huang Bao <eh5@sokka.cn>
Date: Wed, 21 Apr 2021 09:18:13 +0800
Subject: [PATCH] bluez5: cache a2dp volumes activation info

So we don't get a sudden boost on soft volumes when switching profile/codec.
---
 spa/plugins/bluez5/bluez5-dbus.c | 23 ++++++++++++++++-------
 spa/plugins/bluez5/defs.h        |  4 ++++
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/spa/plugins/bluez5/bluez5-dbus.c b/spa/plugins/bluez5/bluez5-dbus.c
index 5b24137b2..68f8eda30 100644
--- a/spa/plugins/bluez5/bluez5-dbus.c
+++ b/spa/plugins/bluez5/bluez5-dbus.c
@@ -1690,22 +1690,27 @@ static void spa_bt_transport_volume_changed(struct spa_bt_transport *transport)
 {
 	struct spa_bt_monitor *monitor = transport->monitor;
 	struct spa_bt_transport_volume * t_volume;
+	int volume_id;
 
 	if (transport->profile & SPA_BT_PROFILE_A2DP_SINK)
-		t_volume = &transport->volumes[SPA_BT_VOLUME_ID_TX];
+		volume_id = SPA_BT_VOLUME_ID_TX;
 	else if (transport->profile & SPA_BT_PROFILE_A2DP_SOURCE)
-		t_volume = &transport->volumes[SPA_BT_VOLUME_ID_RX];
+		volume_id = SPA_BT_VOLUME_ID_RX;
 	else
 		return;
 
+	t_volume = &transport->volumes[volume_id];
+
 	if (t_volume->hw_volume != t_volume->new_hw_volume) {
 		t_volume->hw_volume = t_volume->new_hw_volume;
 		t_volume->volume = spa_bt_volume_hw_to_linear(t_volume->hw_volume,
 					t_volume->hw_volume_max);
 		spa_log_debug(monitor->log, "transport %p: volume changed %d(%f) ",
 			transport, t_volume->new_hw_volume, t_volume->volume);
-		if (spa_bt_transport_volume_enabled(transport))
+		if (spa_bt_transport_volume_enabled(transport)) {
+			transport->device->a2dp_volume_active[volume_id] = true;
 			spa_bt_transport_emit_volume_changed(transport);
+		}
 	}
 }
 
@@ -2537,10 +2542,6 @@ static DBusHandlerResult endpoint_set_configuration(DBusConnection *conn,
 		}
 	}
 
-	/* PW is the rendering device so it's responsible for reporting hardware volume. */
-	if (profile & SPA_BT_PROFILE_A2DP_SOURCE) {
-		transport->volumes[SPA_BT_VOLUME_ID_RX].active = true;
-	}
 	for (int i = 0; i < SPA_BT_VOLUME_ID_TERM; ++i) {
 		transport->volumes[i].hw_volume = SPA_BT_VOLUME_INVALID;
 		transport->volumes[i].hw_volume_max = SPA_BT_VOLUME_A2DP_MAX;
@@ -2556,6 +2557,14 @@ static DBusHandlerResult endpoint_set_configuration(DBusConnection *conn,
 	if (is_new)
 		spa_list_append(&transport->device->transport_list, &transport->device_link);
 
+	if (profile & SPA_BT_PROFILE_A2DP_SOURCE) {
+		/* PW is the rendering device so it's responsible for reporting hardware volume. */
+		transport->volumes[SPA_BT_VOLUME_ID_RX].active = true;
+	} else if (profile & SPA_BT_PROFILE_A2DP_SINK) {
+		transport->volumes[SPA_BT_VOLUME_ID_TX].active
+			|= transport->device->a2dp_volume_active[SPA_BT_VOLUME_ID_TX];
+	}
+
 	if (codec->validate_config) {
 		struct spa_audio_info info;
 		if (codec->validate_config(codec, 0,
diff --git a/spa/plugins/bluez5/defs.h b/spa/plugins/bluez5/defs.h
index 131a319ad..5bc5adbe7 100644
--- a/spa/plugins/bluez5/defs.h
+++ b/spa/plugins/bluez5/defs.h
@@ -424,6 +424,10 @@ struct spa_bt_device {
 	int has_battery;
 
 	uint32_t hw_volume_profiles;
+	/* Even tought A2DP volume is exposed on transport interface, the
+	 * volume activation info would not be variate between transports
+	 * under same device. So it's safe to cache activation info here. */
+	bool a2dp_volume_active[2];
 
 	struct spa_hook_list listener_list;
 	bool added;