extmod/nimble: Allow modbluetooth binding to hook "sent HCI packet".

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) {

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

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