qt-ble: add support to wait for descriptor write completion

When we enable notifications, we actually want to make sure to wait for
that write to have completed before we start communicating with the
device, because otherwise we might lose notification events.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/core/qt-ble.cpp b/core/qt-ble.cpp
index eae10e6b1..0ecad50c3 100644
--- a/core/qt-ble.cpp
+++ b/core/qt-ble.cpp
@@ -92,6 +92,7 @@ void BLEObject::characteristicWritten(const QLowEnergyCharacteristic &c, const Q
 void BLEObject::writeCompleted(const QLowEnergyDescriptor&, const QByteArray&)
 {
 	qDebug() << "BLE write completed";
+	desc_written++;
 }
 
 void BLEObject::addService(const QBluetoothUuid &newService)
@@ -489,6 +490,7 @@ dc_status_t qt_ble_open(void **io, dc_context_t *, const char *devaddr, dc_user_
 			qDebug() << "now writing \"0x0100\" to the descriptor" << d.uuid().toString();
 
 			ble->preferredService()->writeDescriptor(d, QByteArray::fromHex("0100"));
+			WAITFOR(ble->descriptorWritten(), 1000);
 			break;
 		}
 	}