extmod/btstack: Reset pending_value_handle before calling write-done cb.

The pending_value_handle needs to be freed and reset before calling
mp_bluetooth_gattc_on_read_write_status(), which will call the Python IRQ
handler, which may in turn call back into BTstack to perform an action like
a write.  In that case the pending_value_handle will need to be available
for the write/read/etc to proceed.

Fixes issue #13611.
Signed-off-by: Damien George <damien@micropython.org>

extmod/btstack/modbluetooth_btstack.c

@@ -490,11 +490,12 @@ STATIC void btstack_packet_handler_write_with_response(uint8_t packet_type, uint
         if (!conn) {
             return;
         }
-        mp_bluetooth_gattc_on_read_write_status(MP_BLUETOOTH_IRQ_GATTC_WRITE_DONE, conn_handle, conn->pending_value_handle, status);
+        uint16_t value_handle = conn->pending_value_handle;
         conn->pending_value_handle = 0xffff;
         m_del(uint8_t, conn->pending_write_value, conn->pending_write_value_len);
         conn->pending_write_value = NULL;
         conn->pending_write_value_len = 0;
+        mp_bluetooth_gattc_on_read_write_status(MP_BLUETOOTH_IRQ_GATTC_WRITE_DONE, conn_handle, value_handle, status);
     }
 }
 #endif // MICROPY_PY_BLUETOOTH_ENABLE_GATT_CLIENT

tests/multi_bluetooth/ble_irq_calls.py

+# Test calling BLE methods from within the BLE.irq event handler.
+
+from micropython import const
+import struct
+import time
+import bluetooth
+
+_IRQ_CENTRAL_CONNECT = const(1)
+_IRQ_CENTRAL_DISCONNECT = const(2)
+_IRQ_PERIPHERAL_CONNECT = const(7)
+_IRQ_PERIPHERAL_DISCONNECT = const(8)
+_IRQ_GATTC_SERVICE_RESULT = const(9)
+_IRQ_GATTC_SERVICE_DONE = const(10)
+_IRQ_GATTC_CHARACTERISTIC_RESULT = const(11)
+_IRQ_GATTC_CHARACTERISTIC_DONE = const(12)
+_IRQ_GATTC_DESCRIPTOR_RESULT = const(13)
+_IRQ_GATTC_DESCRIPTOR_DONE = const(14)
+_IRQ_GATTC_READ_RESULT = const(15)
+_IRQ_GATTC_READ_DONE = const(16)
+_IRQ_GATTC_WRITE_DONE = const(17)
+_IRQ_MTU_EXCHANGED = const(21)
+_IRQ_GET_SECRET = const(29)
+_IRQ_SET_SECRET = const(30)
+
+EVENT_NAMES = {
+    1: "_IRQ_CENTRAL_CONNECT",
+    2: "_IRQ_CENTRAL_DISCONNECT",
+    3: "_IRQ_GATTS_WRITE",
+    4: "_IRQ_GATTS_READ_REQUEST",
+    7: "_IRQ_PERIPHERAL_CONNECT",
+    8: "_IRQ_PERIPHERAL_DISCONNECT",
+    9: "_IRQ_GATTC_SERVICE_RESULT",
+    10: "_IRQ_GATTC_SERVICE_DONE",
+    11: "_IRQ_GATTC_CHARACTERISTIC_RESULT",
+    12: "_IRQ_GATTC_CHARACTERISTIC_DONE",
+    13: "_IRQ_GATTC_DESCRIPTOR_RESULT",
+    14: "_IRQ_GATTC_DESCRIPTOR_DONE",
+    15: "_IRQ_GATTC_READ_RESULT",
+    16: "_IRQ_GATTC_READ_DONE",
+    17: "_IRQ_GATTC_WRITE_DONE",
+    18: "_IRQ_GATTC_NOTIFY",
+    21: "_IRQ_MTU_EXCHANGED",
+}
+
+_ADV_TYPE_FLAGS = const(0x01)
+_ADV_TYPE_NAME = const(0x09)
+_ADV_TYPE_UUID128_COMPLETE = const(0x7)
+
+_NOTIFY_ENABLE = const(1)
+
+ACCESSORY_UUID = bluetooth.UUID("a5a5a5a5-ffff-9999-1111-5a5a5a5a5a5a")
+STATE_UUID = bluetooth.UUID("a5a5a5a5-eeee-9999-1111-5a5a5a5a5a5a")
+CCC_UUID = bluetooth.UUID(0x2902)
+
+STATE_CHARACTERISTIC = (
+    STATE_UUID,
+    bluetooth.FLAG_READ | bluetooth.FLAG_NOTIFY,
+)
+
+ACCESSORY_SERVICE = (ACCESSORY_UUID, (STATE_CHARACTERISTIC,))
+
+
+class Central:
+    def __init__(self):
+        self.done = False
+        self._conn_handle = None
+        self._service = None
+        self._characteristic = None
+        self._cccd_handle = None
+        ble.active(1)
+        ble.irq(self._ble_event_handler)
+        ble.gap_connect(*BDADDR)
+
+    def _ble_event_handler(self, event, data):
+        print(EVENT_NAMES[event])
+
+        if event == _IRQ_PERIPHERAL_CONNECT:
+            conn_handle, _, _ = data
+            self._conn_handle = conn_handle
+            ble.gattc_discover_services(self._conn_handle, ACCESSORY_UUID)
+
+        elif event == _IRQ_PERIPHERAL_DISCONNECT:
+            conn_handle, _, addr = data
+            assert self._conn_handle == conn_handle
+            self._conn_handle = None
+            print("connection closed")
+
+        elif event == _IRQ_GATTC_SERVICE_RESULT:
+            _, first_handle, last_handle, uuid = data
+            print("service found:", last_handle - first_handle, uuid)
+            if uuid == ACCESSORY_UUID:
+                assert self._service is None
+                self._service = (first_handle, last_handle)
+
+        elif event == _IRQ_GATTC_SERVICE_DONE:
+            print("service handle range:", self._service[1] - self._service[0])
+            start_handle, end_handle = self._service
+            ble.gattc_discover_characteristics(self._conn_handle, start_handle, end_handle)
+
+        elif event == _IRQ_GATTC_CHARACTERISTIC_RESULT:
+            _, end_handle, value_handle, properties, uuid = data
+            assert uuid == STATE_UUID
+            print("characteristic found:", uuid)
+            self._characteristic = (end_handle, value_handle, properties)
+
+        elif event == _IRQ_GATTC_CHARACTERISTIC_DONE:
+            start_handle, end_handle = self._service
+            ble.gattc_discover_descriptors(self._conn_handle, start_handle, end_handle)
+
+        elif event == _IRQ_GATTC_DESCRIPTOR_RESULT:
+            _, dsc_handle, uuid = data
+            if uuid == CCC_UUID:
+                print("CCCD found:", uuid)
+                assert self._cccd_handle is None
+                self._cccd_handle = dsc_handle
+
+        elif event == _IRQ_GATTC_DESCRIPTOR_DONE:
+            # Discovery complete, proceed to MTU exchange.
+            ble.gattc_exchange_mtu(self._conn_handle)
+
+        elif event == _IRQ_MTU_EXCHANGED:
+            # MTU exchanged, proceed to enable CCCD.
+            print("CCCD write")
+            ble.gattc_write(
+                self._conn_handle, self._cccd_handle, struct.pack("<h", _NOTIFY_ENABLE), 1
+            )
+
+        elif event == _IRQ_GATTC_WRITE_DONE:
+            conn_handle, _, result = data
+            print("CCCD write result:", result)
+            _, state_handle, _ = self._characteristic
+            print("issue gattc_read")
+            ble.gattc_read(self._conn_handle, state_handle)
+
+        elif event == _IRQ_GATTC_READ_RESULT:
+            _, _, char_data = data
+            print("gattc_read result:", bytes(char_data))
+
+        elif event == _IRQ_GATTC_READ_DONE:
+            self.done = True
+            ble.gap_disconnect(self._conn_handle)
+
+
+class Peripheral:
+    def __init__(self):
+        self.done = False
+        ble.active(1)
+        ble.irq(self._ble_event_handler)
+        ble.gatts_register_services((ACCESSORY_SERVICE,))
+        add_payload = self.advertising_payload("acc", (ACCESSORY_UUID,))
+        ble.gap_advertise(500000, add_payload)
+
+    def advertising_payload(self, name, services):
+        payload = bytearray()
+
+        def _append(adv_type, value):
+            nonlocal payload
+            payload.extend(struct.pack("BB", len(value) + 1, adv_type) + value)
+
+        _append(_ADV_TYPE_FLAGS, struct.pack("B", 0x02 + 0x04))
+        _append(_ADV_TYPE_NAME, name)
+
+        for uuid in services:
+            b = bytes(uuid)
+            assert len(b) == 16
+            _append(_ADV_TYPE_UUID128_COMPLETE, b)
+
+        return payload
+
+    def _ble_event_handler(self, event, data):
+        if event not in (_IRQ_GET_SECRET, _IRQ_SET_SECRET):
+            print(EVENT_NAMES[event])
+        if event == _IRQ_CENTRAL_DISCONNECT:
+            self.done = True
+
+
+# Acting in peripheral role.
+def instance0():
+    print("peripheral start")
+    peripheral = Peripheral()
+    multitest.globals(BDADDR=ble.config("mac"))
+    multitest.next()
+    while not peripheral.done:
+        time.sleep_ms(100)
+    multitest.broadcast("finished")
+    ble.active(0)
+
+
+# Acting in central role.
+def instance1():
+    print("central start")
+    multitest.next()
+    central = Central()
+    while not central.done:
+        time.sleep_ms(100)
+    multitest.wait("finished")
+    ble.active(0)
+
+
+ble = bluetooth.BLE()

tests/multi_bluetooth/ble_irq_calls.py.exp

+--- instance0 ---
+peripheral start
+_IRQ_CENTRAL_CONNECT
+_IRQ_MTU_EXCHANGED
+_IRQ_GATTS_READ_REQUEST
+_IRQ_CENTRAL_DISCONNECT
+--- instance1 ---
+central start
+_IRQ_PERIPHERAL_CONNECT
+_IRQ_GATTC_SERVICE_RESULT
+service found: 3 UUID('a5a5a5a5-ffff-9999-1111-5a5a5a5a5a5a')
+_IRQ_GATTC_SERVICE_DONE
+service handle range: 3
+_IRQ_GATTC_CHARACTERISTIC_RESULT
+characteristic found: UUID('a5a5a5a5-eeee-9999-1111-5a5a5a5a5a5a')
+_IRQ_GATTC_CHARACTERISTIC_DONE
+_IRQ_GATTC_DESCRIPTOR_RESULT
+_IRQ_GATTC_DESCRIPTOR_RESULT
+_IRQ_GATTC_DESCRIPTOR_RESULT
+CCCD found: UUID(0x2902)
+_IRQ_GATTC_DESCRIPTOR_DONE
+_IRQ_MTU_EXCHANGED
+CCCD write
+_IRQ_GATTC_WRITE_DONE
+CCCD write result: 0
+issue gattc_read
+_IRQ_GATTC_READ_RESULT
+gattc_read result: b''
+_IRQ_GATTC_READ_DONE
+_IRQ_PERIPHERAL_DISCONNECT
+connection closed