Add interoperability mechanism to restrict the AVDTP MTU for AAC codec

Also, add an interoperability entry for devices that are known
to have AAC-related issues.

Test: A2DP streaming to Headsets
Bug: 63725151
Change-Id: Ic9b6640da44ebc28bfa63a19a87f0543d69bc576
(cherry picked from commit b866da0bc1254103146912077bcb49128963dee7)

2 files changed, 25 insertions, 0 deletions

diff --git a/device/include/interop_database.h b/device/include/interop_database.h
index bac07397b..f722cf45b 100644
--- a/device/include/interop_database.h
+++ b/device/include/interop_database.h
@@ -67,6 +67,9 @@ static const interop_addr_entry_t interop_addr_database[] = {
     {{{0x44, 0x5e, 0xf3, 0, 0, 0}}, 3, INTEROP_DISABLE_ABSOLUTE_VOLUME},
     {{{0xd4, 0x9c, 0x28, 0, 0, 0}}, 3, INTEROP_DISABLE_ABSOLUTE_VOLUME},
 
+    // Bose QuiteComfort 35, SoundSport and similar (because of older firmware)
+    {{{0x04, 0x52, 0xc7, 0, 0, 0}}, 3, INTEROP_2MBPS_LINK_ONLY},
+
     // JayBird Family
     {{{0x00, 0x18, 0x91, 0, 0, 0}}, 3, INTEROP_2MBPS_LINK_ONLY},
 
diff --git a/stack/a2dp/a2dp_aac_encoder.cc b/stack/a2dp/a2dp_aac_encoder.cc
index 9c695885e..6c7914994 100644
--- a/stack/a2dp/a2dp_aac_encoder.cc
+++ b/stack/a2dp/a2dp_aac_encoder.cc
@@ -37,6 +37,12 @@
 // A2DP AAC encoder interval in milliseconds
 #define A2DP_AAC_ENCODER_INTERVAL_MS 20
 
+/*
+ * 2DH5 payload size of:
+ * 679 bytes - (4 bytes L2CAP Header + 12 bytes AVDTP Header)
+ */
+#define MAX_2MBPS_AVDTP_MTU 663
+
 // offset
 #if (BTA_AV_CO_CP_SCMS_T == TRUE)
 #define A2DP_AAC_OFFSET (AVDT_MEDIA_OFFSET + 1)
@@ -222,6 +228,22 @@ static void a2dp_aac_encoder_update(uint16_t peer_mtu,
       a2dp_aac_encoder_cb.feeding_params.sample_rate;
   p_encoder_params->channel_mode = A2DP_GetChannelModeCodeAac(p_codec_info);
 
+  LOG_VERBOSE(LOG_TAG, "%s: original AVDTP MTU size: %d", __func__,
+              a2dp_aac_encoder_cb.TxAaMtuSize);
+  if (a2dp_aac_encoder_cb.is_peer_edr &&
+      !a2dp_aac_encoder_cb.peer_supports_3mbps) {
+    // This condition would be satisfied only if the remote device is
+    // EDR and supports only 2 Mbps, but the effective AVDTP MTU size
+    // exceeds the 2DH5 packet size.
+    LOG_VERBOSE(LOG_TAG,
+                "%s: The remote device is EDR but does not support 3 Mbps",
+                __func__);
+    if (peer_mtu > MAX_2MBPS_AVDTP_MTU) {
+      LOG_WARN(LOG_TAG, "%s: Restricting AVDTP MTU size from %d to %d",
+               __func__, peer_mtu, MAX_2MBPS_AVDTP_MTU);
+      peer_mtu = MAX_2MBPS_AVDTP_MTU;
+    }
+  }
   uint16_t mtu_size = BT_DEFAULT_BUFFER_SIZE - A2DP_AAC_OFFSET - sizeof(BT_HDR);
   if (mtu_size < peer_mtu) {
     a2dp_aac_encoder_cb.TxAaMtuSize = mtu_size;