extmod/nimble: Make stm32 and unix NimBLE ports use synchronous events.

This changes stm32 from using PENDSV to run NimBLE to use the MicroPython
scheduler instead.  This allows Python BLE callbacks to be invoked directly
(and therefore synchronously) rather than via the ringbuffer.

The NimBLE UART HCI and event processing now happens in a scheduled task
every 128ms.  When RX IRQ idle events arrive, it will also schedule this
task to improve latency.

There is a similar change for the unix port where the background thread now
queues the scheduled task.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/extmod/nimble/modbluetooth_nimble.c b/extmod/nimble/modbluetooth_nimble.c
index 7ee6ae867..c961aee32 100644
--- a/extmod/nimble/modbluetooth_nimble.c
+++ b/extmod/nimble/modbluetooth_nimble.c
@@ -382,6 +382,7 @@ int mp_bluetooth_init(void) {
     mp_bluetooth_nimble_ble_state = MP_BLUETOOTH_NIMBLE_BLE_STATE_WAITING_FOR_SYNC;
 
     // Initialise NimBLE memory and data structures.
+    DEBUG_printf("mp_bluetooth_init: nimble_port_init\n");
     nimble_port_init();
 
     // Make sure that the HCI UART and event handling task is running.
@@ -402,6 +403,8 @@ int mp_bluetooth_init(void) {
         return MP_ETIMEDOUT;
     }
 
+    DEBUG_printf("mp_bluetooth_init: starting services\n");
+
     // By default, just register the default gap/gatt service.
     ble_svc_gap_init();
     ble_svc_gatt_init();
@@ -417,7 +420,7 @@ int mp_bluetooth_init(void) {
 }
 
 void mp_bluetooth_deinit(void) {
-    DEBUG_printf("mp_bluetooth_deinit\n");
+    DEBUG_printf("mp_bluetooth_deinit %d\n", mp_bluetooth_nimble_ble_state);
     if (mp_bluetooth_nimble_ble_state == MP_BLUETOOTH_NIMBLE_BLE_STATE_OFF) {
         return;
     }