From edfb5d56c8392b1c0933abf49e757b90f2c07859 Mon Sep 17 00:00:00 2001
From: Jim Mussared <jim.mussared@gmail.com>
Date: Wed, 21 Jul 2021 17:04:41 +1000
Subject: [PATCH] extmod/nimble: Allow modbluetooth binding to hook "sent HCI
 packet".

---
 extmod/nimble/hal/hal_uart.c        | 6 ++++++
 extmod/nimble/modbluetooth_nimble.c | 3 +++
 extmod/nimble/modbluetooth_nimble.h | 3 +++
 3 files changed, 12 insertions(+)

diff --git a/extmod/nimble/hal/hal_uart.c b/extmod/nimble/hal/hal_uart.c
index cd5e49e30b..84a964fde9 100644
--- a/extmod/nimble/hal/hal_uart.c
+++ b/extmod/nimble/hal/hal_uart.c
@@ -27,6 +27,7 @@
 #include "py/runtime.h"
 #include "py/mphal.h"
 #include "nimble/ble.h"
+#include "extmod/nimble/modbluetooth_nimble.h"
 #include "extmod/nimble/hal/hal_uart.h"
 #include "extmod/nimble/nimble/nimble_npl_os.h"
 #include "extmod/mpbthci.h"
@@ -74,6 +75,11 @@ void hal_uart_start_tx(uint32_t port) {
     #endif
 
     mp_bluetooth_hci_uart_write(mp_bluetooth_hci_cmd_buf, len);
+
+    if (len > 0) {
+        // Allow modbluetooth bindings to hook "sent packet" (e.g. to unstall l2cap channels).
+        mp_bluetooth_nimble_sent_hci_packet();
+    }
 }
 
 int hal_uart_close(uint32_t port) {
diff --git a/extmod/nimble/modbluetooth_nimble.c b/extmod/nimble/modbluetooth_nimble.c
index 8bbec54881..f3679354f4 100644
--- a/extmod/nimble/modbluetooth_nimble.c
+++ b/extmod/nimble/modbluetooth_nimble.c
@@ -1392,6 +1392,9 @@ int mp_bluetooth_gattc_exchange_mtu(uint16_t conn_handle) {
 
 #endif // MICROPY_PY_BLUETOOTH_ENABLE_GATT_CLIENT
 
+void mp_bluetooth_nimble_sent_hci_packet(void) {
+}
+
 #if MICROPY_PY_BLUETOOTH_ENABLE_L2CAP_CHANNELS
 
 // Fortunately NimBLE uses mbuf chains correctly with L2CAP COC (rather than
diff --git a/extmod/nimble/modbluetooth_nimble.h b/extmod/nimble/modbluetooth_nimble.h
index 9ed64368b2..15648a9959 100644
--- a/extmod/nimble/modbluetooth_nimble.h
+++ b/extmod/nimble/modbluetooth_nimble.h
@@ -71,5 +71,8 @@ void mp_bluetooth_nimble_port_start(void);
 // Tell the port to stop its background task.
 void mp_bluetooth_nimble_port_shutdown(void);
 
+// --- Called by the HCI UART layer to let us know when packets have been sent.
+void mp_bluetooth_nimble_sent_hci_packet(void);
+
 
 #endif // MICROPY_INCLUDED_EXTMOD_NIMBLE_MODBLUETOOTH_NIMBLE_H